.NET Reference

My.Resources in C#

2011-11-16T13:32:00.001-08:00

The equivalent of:

My.Resources

in VB.NET is:

Properties.Resources

in C#.

So,

Me.Icon = My.Resources.AppIcon

in VB.NET is equivalent to:

this.Icon = Properties.Resources.App_Icon;

in C#.

Computing RGB composite Color Value in C#

2011-10-21T12:48:00.000-07:00

If you still have to deal with the Win32Api in C#, you may need to get the old-style RGB composite color values from a .NET Color value. The ToArgb method doesn't work like you want, so it has to be computed:

  private int ConvertColorToRGB(Color col)
    {
    return (col.R) | (col.G << 8) | (col.B << 16);
    }

If you are using VB.NET, it still has an RGB function to call.

Updating the NUM_ROWS in USER_TABLES in Oracle

2011-08-25T08:10:00.000-07:00

Good or bad, I use the NUM_ROWS values in the USER_TABLES table to help filter lists of tables when presenting them to the user. If I have a database and only about 25% of tables have records (and there are thousands of tables), then it is a lot nicer to only sift through the tables that do have records, and knowing how many records is even better (even if it is only an estimate). My problem is that these values don't just get updated automatically for you. You might find that they are all 0 even when there is data present. You can update all of the values with something like this:

exec dbms_stats.gather_schema_stats('mySchema', cascade=>TRUE)

A lot more info on this topic can be found at:

http://www.dba-oracle.com/concepts/tables_optimizer_statistics.htm

Creating a .CSV file in ASP.NET

2011-07-18T10:13:00.000-07:00

I wanting to create a .CSV file from a query to SQL Server in ASP.NET. The link below has an excellent description of creating the .CSV file without having to create a temp file like I was originally planning to do. This post doesn't show how to wrap the query results up, but that is pretty simple to figure out:

http://wiki.asp.net/page.aspx/401/export-to-csv-file/

Selecting a Folder in VB.NET

2011-07-14T10:20:00.000-07:00

To go along with my previous post on the Open File and Save File dialogs in VB.NET, I am providing this post using FolderBrowserDialog to select a specific Directory.

Browsing to Select a Directory in VB.NET

     Dim dirDlg As New FolderBrowserDialog

      dirDlg.RootFolder = Environment.SpecialFolder.MyComputer

      If dirDlg.ShowDialog() = DialogResult.OK Then

          ' do something with the selected path
          Debug.Print("Directory: " + dirDlg.SelectedPath)

      Else

          ' the dialog was cancelled

      End If

The FolderBrowsingDialog object has many options, but I have only shown the most commonly used one in the example. The RootFolder property lets you specify the directory to start browsing from. You can set this property to an explicit path (like "c:\MyData") or you can use the special directories that are defined for you:

Environment.SpecialFolder.MyDocument
Environment.SpecialFolder.MyComputer
Environment.SpecialFolder.MyPictures
Environment.SpecialFolder.Desktop

The default is Environment.SpecialFolder.MyComputer.

After the ShowDialog call returns OK, use the SelectedPath property to get the selected directory.

Selecting Files to Open or Save in VB.NET

2011-07-14T07:24:00.000-07:00

VB.NET has come a long way from the clunky Common Dialog control of VB6 for implementing a standard dialog that will let you browse to find a file to Open or Save. Here is an example of each:

Browsing to Open a File in VB.NET

      Dim fileDlg As New OpenFileDialog

 fileDlg.Filter = "CSV File (*.csv)|*.csv|txt files (*.txt)|*.txt|All files (*.*)|*.*"
 fileDlg.DefaultExt = "csv"

' could be omitted to use default, or a specific dir can be given
 fileDlg.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)

 If fileDlg.ShowDialog() = DialogResult.OK Then

     ' Do something with the selected filename
     Debug.Print(fileDlg.FileName)

 Else

     ' the dialog was cancelled

 End If

The OpenFileDialog object is used here, and I have only shown the most commonly used options. The Filter property lets you specify the which File Types will be selectable form the Open File Dialog (in a dropdown list). The value is set to a string that is a pipe (|) delimited list composed to a File Type Description and Filter Pattern. If you have more than one File Type, you can add another pipe, then another Description|Filter Pattern, and so on. If you leave the Filter property empty, then then Open File Dialog will just not have a drop down to select the File Type filter. Here are some examples:

"CSV File (*.csv)|*.csv"
"CSV File (*.csv)|*.csv|txt files (*.txt)|*.txt"
"CSV File (*.csv)|*.csv|txt files (*.txt)|*.txt|All files (*.*)|*.*"

If you are using Filter with more than one File Type specified, you can also use DefaultExt to specify which File Type to use as the default. Just specify the extension as a string (with no dot). This property also will set the default file extension to use if you don't specify it in the filename (if typed in), so this property can also be used without the Filter property being set.

The InitialDirectory property will let you define which directory to open up in. You can set this property to an explicit path (like "c:\MyData") or you can use the special directories that are defined for you, like:

Environment.SpecialFolder.MyDocument
Environment.SpecialFolder.MyComputer
Environment.SpecialFolder.MyPictures
Environment.SpecialFolder.Desktop

There is also a Title property that can be used to change the name of the Open File Dialog. In this example, it is not used and defaults to "Open File".

After the ShowDialog call returns OK, use the FileName property to get the selected filename.

Browsing to Save a File in VB.NET

   Dim fileDlg As New SaveFileDialog

 fileDlg.Filter = "CSV File (*.csv)|*.csv|txt files (*.txt)|*.txt|All files (*.*)|*.*"
 fileDlg.DefaultExt = "csv"

 ' InitialDirectory can be omitted to use default, or used to specify an explicit directory
 fileDlg.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)

 fileDlg.OverwritePrompt = True

 If fileDlg.ShowDialog() = DialogResult.OK Then

     ' Do something with the selected filename
     Debug.Print(fileDlg.FileName)

 Else

     ' the dialog was cancelled

 End If

Saving a file is similar to opening a file. You use a SaveFileDialog object instead of a OpenFileDialog object. Many of the properties work the same way as with the OpenFileDialog such as Filter, DefaultExt, and InitialDirectory. I also show OverwritePrompt set to True (which is the default). This setting will cause the dialog to prompt you when you try to save over an existing file.

After the ShowDialog call returns OK, use the FileName property to get the filename.

If you want to select a Directory instead of a file, look at this post.

Setting all elements of an Array to Null in C# (like with memset in C++)

2011-07-13T13:11:00.000-07:00

I sometime find it strange that things we take for granted in C++ are hard in C#. Probably I should say hard to find the equivalent for rather than hard to do. I routinely clear out my arrays in C++ with memset (setting each item to 0). To get the equivalent in C#, you can use the Array.Clear(...) method like this:

Array.Clear(MyArray,0,MyArray.Length);

Here is a more detailed example:

http://www.dotnetperls.com/array-clear

Preventing Flicker with GDI+ drawing in C#

2011-07-12T11:43:00.000-07:00

In C#, the OnPaintBackground method is called before the OnPaint event and it draws the background color for the entire view. If you are already drawing the background in the OnPaint event, then this process will cause flicker. You can override the OnPaintBackground and just do nothing in it to prevent the flicker:

protected override void OnPaintBackground(PaintEventArgs pevent)
{
// do nothing
}

Script to Purge All Objects for a User in Oracle

2011-06-29T08:13:00.000-07:00

I have to purge and reload an Oracle Database dump on a monthly basis. I have been manually deleting all of the Objects with Toad before loading the new dump. I searched for a script that would delete all of the objects. Many people suggested that you should just drop the user, but if I do this I have to add back in grants that don't get picked up by the export.

This thread on the Oracle Discussion Forum has several solutions. I am pasting the script that worked the best for me below from Massimo. There is some criticism in the thread about why he did not just use the object name in one case instead of all the If/Else conditions; however, I like this approach better, because I can easily take out something if I need to:


declare
stringa varchar2(100);

cursor cur is
      select  *
      from    user_objects;

begin
  for c in cur loop
    begin
      stringa := '';
      if c.object_type = 'VIEW' then
          stringa := 'drop view ' || c.object_name;
          EXECUTE immediate stringa;
      elsif c.object_type = 'TABLE' then
          stringa := 'drop table ' || c.object_name || ' cascade constraints';
          EXECUTE immediate stringa;
      elsif c.object_type = 'SEQUENCE' then
          stringa := 'drop sequence ' || c.object_name;
          EXECUTE immediate stringa;
      elsif c.object_type = 'PACKAGE' then
          stringa := 'drop package ' || c.object_name;
          EXECUTE immediate stringa;   
      elsif c.object_type = 'TRIGGER' then
          stringa := 'drop trigger ' || c.object_name;
          EXECUTE immediate stringa;   
      elsif c.object_type = 'PROCEDURE' then
          stringa := 'drop procedure ' || c.object_name;
          EXECUTE immediate stringa;
      elsif c.object_type = 'FUNCTION' then
          stringa := 'drop function ' || c.object_name;
          EXECUTE immediate stringa;     
      elsif c.object_type = 'SYNONYM' then
          stringa := 'drop synonym ' || c.object_name;
          EXECUTE immediate stringa;
      elsif c.object_type = 'INDEX' then
          stringa := 'drop index ' || c.object_name;
          EXECUTE immediate stringa;
      elsif c.object_type = 'PACKAGE BODY' then
          stringa := 'drop PACKAGE BODY ' || c.object_name;
          EXECUTE immediate stringa;  
      elsif c.object_type = 'DATABASE LINK' then
          stringa := 'drop database link ' || c.object_name;
          EXECUTE immediate stringa;  
      end if;
  exception
        when others then
        null;
    end; 
  end loop;
  -- PURGE recyclebin

end;
/

Convert char[] to String in c#

2011-06-28T13:49:00.000-07:00

If you have something like:


char [] chArray = infile.ReadChars(10);


char[] chArray = new char[] {'t','e','s','t'};

and you want to convert it to a String, I always (incorrectly) try:


String str = chArray.ToString();

and it doesn't work (you get "System.Char[]").

You have to say something like this:


String str = new String(chArray);

Importing a Datapump export into Oracle with IMPDP

2011-06-26T16:26:00.000-07:00

I never had to remember the command-line options for the old imp utility (because it prompted you for the info it needed), but with impdp, you need to know what to specify. Here is my simple example that works for me to import a Datapump export file:

impdp user/password schemas=mySchema dumpfile=myfile.dpdmp logfile=mylog.log

The schema parameter specifies which schema from the file to import.

The dumpfile parameter specifies the name of the datapump export file to import. The catch here is that the dump file location defaults to a default directory on the server (something like this):

c:\oracle\Administrator\admin\orcl\dpdump

You can change this path, but you have to create the directory in Oracle and specify it with a Directory Parameter. You have to create a directory in Oracle with something like this:

create directory MyExportDir as 'c:\exports';

Here is the detailed info for impdp on the Oracle site.

Creating a Tablespace in Oracle with SQL

2011-06-26T16:23:00.000-07:00

I never can seem to remember the SQL to create a tablespace in Oracle. I am posting my example that I use to I can easily find it again in the future:

create tablespace MyTableSpaceName
logging
datafile 'MyTableSpaceFile.dbf'
size 32m
autoextend on
next 32m maxsize unlimited
extent management local;

Oracle Function to Read SDO_ORDINATE Values without causing Exception in .NET

2011-06-26T14:44:00.000-07:00

Below is an Oracle function to read a specified SDO_ORDINATE value in an SDO_GEOMETRY attribute so that ODP.NET can handle them without causing an Arithmetic Overflow Exception in .NET when the Oracle NUMBER value has too many digits after the decimal place for a .NET Decimal value.

Most of this function comes from this thread on the Oracle Discussion Forum:

CREATE OR REPLACE function Get_Ordinate_Value(geom sdo_geometry, vPos number default 1) return number
  is
  begin

    if geom is null
    then
       return null;
    end if;

    if vPos <1 or vPos >geom.sdo_ordinates.count()
    then
      return null;
    end if;

    return round(geom.sdo_ordinates(vPos ),8);
  end;
/

Using the Function is something like this where I am getting the origin point and orientation vector for a 3D Oriented Point geometry:

select Get_Ordinate_Value(MyGeomAttr,1) as X,
        Get_Ordinate_Value(MyGeomAttr,2) as Y,
        Get_Ordinate_Value(MyGeomAttr,3) as Z,
        Get_Ordinate_Value(MyGeomAttr,4) as AngleX,
        Get_Ordinate_Value(MyGeomAttr,5) as AngleY,
        Get_Ordinate_Value(MyGeomAttr,6) as AngleZ
from MyTable

This function is pretty simple. I first check to see if the geometry attribute is Null and return Null if it is. I found that if I did not do this, you will get a geometry attribute that is Null passed into the function and you get a "ORA-06531: Reference to uninitialized collection" and it is sometimes hard to tell where it is coming from.

Then the index is checked to see that it is in range for the SDO_ORDINATE array.

I finally use the Round function to reduce the number of digits after the decimal point to a number that the .NET Decimal type can handle.

How to use SQL to retrieve the Vertex values in an SDO_GEOMETRY Attribute

2011-06-26T14:15:00.000-07:00

It turns out to be more complicated than you might think to simply retrieve the Vertices of an SDO_GEOMETRY attribute in Oracle Spatial using just SQL. The main problem is that this is an array of an unknown size, so the solution below is just for retrieving the Ordinate values for 1 record identified by a key and each record returned is one Ordinate in the list.

SELECT Round(COLUMN_VALUE,8) as pt
FROM TABLE( SELECT a.MyGeomAttr.SDO_ORDINATES
                    FROM MyTable a
                    WHERE MyKey=24974)

which will retrieve something like this (my example uses a 3D geometry so there are 3 value per vertex with Z being 0 in all of them):

I will go through why I did the things I did to make this work like I wanted below.

If you are using ODP.NET and you have Oracle Number values in the Ordinates that are larger than a .NET Decimal value (this is common for me), you must use Round (or truncate the value in someway) so that you don't get an Arithmetic Overflow when the Ordinate Value is loaded into a .NET decimal value. I am using the Round function to simply get 8 decimal points of precision). It turns out that the data I have uses Oriented Points and the computed vector coordinates use a large number of decimal places that .NET Decimals can't handle.

To get the Ordinate Values back as the Query results, you must use the TABLE function to convert the SDO_ORDINATES Array to records. See here for more info on the TABLE function. The key thing here is that the COLUMN_VALUE is not just me making up a name for my example, it is a keyword that lets you refer to the value the Table function returns (otherwise you can't run the results of the Table function through the Round function).

The alias "a" seems to be required or you get an error in the query.

Counting Unique (Distinct) Records with SQL

2011-06-26T14:06:00.000-07:00

Using SQL to count all records in a table:


select count(*) from MyTable

Using SQL to count all records in a table with unique/distinct values in a particular attribute:


select count(distinct MyId) from MyTable

Auto-Incrementing Assembly and File version in Visual Studio

2011-06-22T07:38:00.000-07:00

I made a post on this topic some time ago. I still find it incredible that Visual Studio (2005, 2008, 2010) doesn't provide a way to automatically increment the File Version number in an Assembly. Why is this important? To me, the Setup and Deployment project will not deliver a file if the file version is the same (even if the file is newer, different, etc.). It is very easy to forget to go manually update the assembly's File Version, and you don't find out about it until your users install the updated application and see no difference.

The method I posted before works fine, but it is a little complicated to setup and get going.

The new method I found is much easier to setup and use:

http://autobuildversion.codeplex.com/

What's new for Developers in Mango (and RIP .NET CF)

2011-05-25T09:32:00.000-07:00

TechEd 2011 made me reminisce about my old frienemy the .NET Compact Framework. I will eulogize: Friends and fellow developers, we are here today to pay tribute to our friend of almost 10 years. We were coached, pushed, begged, and commanded to embrace you as you made life so much better for us. Yes, we had to be convinced of that, and we hated you at first. You could not go out without a healthy dose of p/invokes, work-arounds, and patches, but we managed to somehow embrace you as your capabilities grew. Now, you are gone. Plucked from us without notice.

I feel almost as sorry for CF as I did for myself after Microsoft threw its mobile developers under the bus last year when we were told there was no upgrade path from Windows Mobile to Windows Phone 7 (WP7). After stewing on this new direction last year, I have finally come to the conclusion that the abandonment of Window Mobile was actually a good thing. No, I have not embraced WP7. I had never seen another Windows Phone in the wild until I when to TechEd 2011 in Atlanta (and I have had my Samsung Focus since November 2010). Needless to say, the popularity of WP7 is so low it would be risky to venture off in that direction at this time. I am sure others feel the same way. One session at the conference said the ComScores for March 2011 placed Windows Mobile 6 together with WP7 at a 7.5% share of the smartphones in the US (and that is a total of 72.5 million smartphone users). Just for comparison, Android was 34.7%, RIM was 27.1%, and Apple was 25.5%. Since probably half of Microsoft’s 7.5% share is Windows Mobile, that leaves a paltry base of users to target (close to the Palm share of 2.8%). How many palm apps are people writing today? Now, you may ask why I think Microsoft’s throwing its mobile developers under the bus is a good thing. Well, it forced me to go develop for Android, BlackBerry, and iOS. I have traded my less than 7.5% Microsoft base for a 87.3% base. I may one day consider WP7 for my applications, but not today. The moral of the story for Microsoft is that if you tell your developers that they are going to have to rewrite their applications from scratch to run on the new version of the platform, they might spend those resources rewriting their apps for another platform (like Android). This business pattern is unfortunately pretty common (look at Intergraph’s upgrade from FRAMME to G/Technology).

Compiled from various sessions at TechEd, I will run down the list of the major new features Windows Phone will include for developers in its next released (called Mango):

Currently, the development platform is a subset of Silverlight 3 or a subset of XNA. The Silverlight 3 subset is being upgraded to a Silverlight 4 subset. There was also talk of blending Silverlight and XNA together to overcome problems in each. This blending will be at a page level (mixing Silverlight and XNA pages together in the same app) and at an element level (putting Silverlight elements on a XNA page, such as text). Regardless, it seems like a crazy mash up on many different levels.

From the Silverlight 4 upgrade, new features will include: implicit styles, data binding enhancements, and ICommand support.

New interfaces will be available for the camera. This feature should finally overcome one of my biggest complaints with WP7, my QR Code scanner app is pretty much useless when you have to take a picture instead of just “scanning”. Why wasn’t this in the first version?

A new Read-only Rich Text Box.

Clipboard API.

Tap, Double Tap, and Hold Events for Text Box.

Red Squiqqlies for misspelled words in a Text Box.

Support for Sockets which fills another big hole in the current version.

Video Brush so you can draw video on a page.

Live Tiles get a new API that allows them to be more accessible and provides new features like text on the Back of a Tile (these tiles flip over periodically to show what is on the back). Single apps can now have multiple tiles and the tiles can deep link to a specific page in the app. App can also control the pinning and unpinning of the tiles from the start page. Also, push notification can happen every 15 minutes instead of an hour, and there can now be 30 push notification endpoints instead of 15. There is supposed to be support for animation like the Xbox Live and People tiles too.

Push Notification Toast can Deep Link to pages in an app too.

There is supposed to be some multitasking and background processing too, but I wasn’t too clear on what this would be. Not having apps like Twitter or IM clients running in the background in the current version really kills the phone’s usefulness for most people.

Beyond the new features for Developers, Mango will also have the following enhancements:

Windows Phone 7 apps will run in a special mode to keep them compatible with the new version.

32 BPP support for images, but defaults to 16 BPP. This feature can be used to fix banding problems with gradient shading (at the expense of performance).

Improved battery usage for Video Player which will now draw at ¾ size and scales up (with restrictions like must be right aligned)

Input thread introduced in ListBox to improve scrolling.

Improvements to memory management that will reduce memory usage in an app by 20 to 30%.

Off-thread Image decoding will allow ListBoxes with images to display and then fill in the images without hanging up.

Internet Explorer will be upgraded to IE9.

Rendering and Input for all languages will be supported.

Personally, I really like my Windows Phone as a phone. I find it unfortunate that it is too unpopular to invest any resources into developing apps for it. I think the Mango update will certainly help overcome its faults and maybe Nokia will eventually disseminate enough of these phones that their share of the market will be worthwhile. However, realigning development efforts to match the smartphone marketshare is unfortunately more urgent than waiting for Microsoft’s platform to come up to speed.

Center a Control on a Form in .NET

2011-02-22T09:27:00.000-08:00

It turns out to be very easy to center a control on a .NET form. Just un-anchor the control from any side and it will center from its position. If you just un-anchor from the left and right it will center horizontally, and if you just un-anchor from the top and bottom, it will center vertically. Un-anchor from all sides and it will center on the form.

More info at:

http://stackoverflow.com/questions/491399/c-centering-controls-within-a-form-in-net-winforms

How solve the Problem of loading a Native DLL when using ASP.NET

2011-02-11T12:42:00.000-08:00

I have had the problem of getting ASP.NET to use a Native DLL for years. I have even posted my complaints in a previous post. My quick and dirty solution has been to simply add the path that contains my DLL to the PATH environment variable and the process would find the .dlls that way. However, if you are using a hosted ASP.NET site or have clients that simply will NOT modify the PATH environment variable, the work around does not work. I have finally found the holy grail of information on how to solve this problem. Why I have not found it before I do not know, and I have search with Google for it a hundred times.

Here is the post I found:

http://blogs.msdn.com/b/jorman/archive/2007/08/31/loading-c-assemblies-in-asp-net.aspx

For ASP.NET, the solution is very simple and elegant. I copy it directly from Jerry Orman's excellent post:

In web.config, add the following…use a path where the Native C++ DLL is located:
<appsettings><add key="NativePath" value="C:\MyNativeDLLs"> </add>

In global.asax, add the following:

protected void Application_Start(object sender, EventArgs e){
String _path = String.Concat(System.Environment.GetEnvironmentVariable("PATH"), ";", ConfigurationSettings.AppSettings["NativePath"]);
System.Environment.SetEnvironmentVariable("PATH", _path, EnvironmentVariableTarget.Process);
}

This post also details other ways of solving the problem as well.

Reading App Settings from the Web.Config

2010-12-01T14:05:00.000-08:00

For a Web Service that needs to read information form the web.config file (in its own virtual directory), the following is all you need to read the information:

using System.Configuration;
.
.
.
String value = ConfigurationManager.AppSettings["Param_1"].ToString();

The web.config file would contains something like this:

For more information, go to the following links:

http://www.dotnetfunda.com/articles/article13.aspx

The following link show how to read the root web.config file instead of the one in the virtual directory:

http://msdn.microsoft.com/en-us/library/610xe886.aspx

Creating Fixed Spaced Fonts for .NET

2010-08-25T16:46:00.000-07:00

How to create a fixed space (mono spaced) font for .NET:

Dim f as Font = new Font(FontFamily.GenericMonospace, 12)

Windows Phone 7 - The Haves and the Have-Nots

2010-06-14T07:36:00.000-07:00

While Windows Phone 7 (WP7) sounds intriguing as a platform for iPhone-type applications, TechEd 2010 was very illuminating on the many things that this new platform does not include and why you will unlikely be able to migrate your existing Windows Mobile applications forward. Let me go through the laundry list of the have-nots:

No native code support. Silverlight 3.0 and XNA are the only ways to develop applications for WP7. If you are not developing games, then Silverlight is probably the path you will be forced to take.

No Database support. SQL Server Compact is not part of WP7. Nor will SQLite or any other 3rd party database engine run either. One TechEd session had the gall to suggest that we should all use collections of objects and Linq as a replacement for SQL Server Compact. Access to data is only available through Web Services and what the application can store in Silverlight’s Isolated Storage. No one would confirm or deny that database support would ever be added to WP7.

No Side Loading Applications. Except for development mode, applications can only be loaded to WP7 devices through the Microsoft Marketplace. It doesn’t matter if the app if for internal use in your organization or not. Also, it is not free to use the Microsoft Marketplace.

Application approval is required. Microsoft claims that it will not be a blackbox like Apple where you stick an app in and hope it comes out; however, they also said they there is a list of applications types that will not be allowed. VOIP was they only example provided.
No access to data on SD cards. Since Silverlight applications can only use isolated storage, there is no way for an application to access information on an SD card. While some devices may support an SD card, the additional memory will apparently be made available for isolated storage, but you can’t preload the content.

No File System support. Again only Isolated Storage is available to a Silverlight app.
No RAPI support. There will no interacting with a WP7 device via the desktop. Obviously there will be some synchronization with Outlook, but nothing the developer will have control of.
Applications must be Silverlight 3. Silverlight 4 will not be available for WP7.
Out of Browser Silverlight support only. Silverlight is not going to be supported in browser on the phone.
Default Browser must be Internet Explorer. While Microsoft claimed that other browsers will be allowed on the phone, they can’t be the default. This is probably okay as long as the new Internet Explorer is better than the Windows Mobile version; however, is it possible to write a viable browser in Silverlight or XNA?
No Bluetooth API. While there is going to be Bluetooth support on the phone, there is no Bluetooth API.
No inter-process communications (IPC) and no Socket support.
No Video Capture Support. Phones will have a camera but not video capture support, and also no video brush.
No Outside TrueType Fonts - Microsoft experts claimed that you will not be able to use TrueType fonts other than the ones delivered with the device. This limitation makes since, how would you get them on the device. While there is supposed to be support for embedding TrueType fonts in your xap file in Silverlight 4, this will not be the version used on the device.

The TechEd demos of WP7 applications had a common theme; they crashed, hung up, or gave peculiar error messages. For a platform that is going to be delivered in the October timeframe (3 months away), it is hard to have much short-term faith in the new platform.

On the positive side, the list is not quite as long:

The Silverlight apps running on the phones looked good even if they were only Silverlight 3.

Lots of different soft input panels (SIPs) provided like numeric, URL, email, etc.

Built-in support and APIs for multi-touch, accelerometers, vibrator, microphone, and camera.
Phones are not going to be feature locked like Windows Mobiles. They should be upgradable like the iPhone.

Applications on the phones do not have the strange isolated storage limits that desktop Silverlight applications have.

Microsoft continually offered up that they were so rushed to get this phone to market that they had to leave a lot of things out. Since the phones are not feature locked (so they claim), maybe there will be a quick release cycle of new versions to fill in the missing components. If you are not planning on developing iPhone type applications (casual games or casual apps usually requiring a connection to a backend), you may be stuck waiting for a new release will new features (or jumping ship to Android or the iPhone). The WP7 platform as it is depicted today will not be able to support the sophisticated applications that are currently running on Windows Mobile, so it cannot be thought of as a successor to the Window Mobile platform. There are many new and great things you can do on WP7, but this constitutes a different kind of platform (one to compete with the iPhone). Will it grow to be a successor to Windows Mobile? How long will this take? What if it flops against the iPhone and never takes hold? Too many questions around the platform to invest a significant amount of development into it if you are not focused on creating iPhone type apps.

***** Since I posted this blog entry, I went to another TechEd and wrote another more updated post.

Preventing Tabs from being Selected

2010-06-02T16:35:00.000-07:00

I tried several solutions I found on the internet to prevent tabs from being selected with a TabControl, but the link below shows the only solution that worked well. My task was very simple, I didn't want the user to select other tabs until the first tab contained valid information. The trick was to use the Deselecting event on the TabControl. In the event, see which tab you are on (SelectedIndex) and perform your validation specific to the tab. If the validation fails, set the event's e.Cancel to True and the tab won't change.

http://www.experts-exchange.com/Programming/Languages/.NET/Visual_Studio_.NET_2005/Q_23411323.html

XPath Query Syntax

2010-06-01T09:48:00.000-07:00

The following link give a good review of the XPath Query syntax:

http://www.codeguru.com/cpp/data/mfc_database/xml/article.php/c7589__1/NET-and-XML-Part-1mdashXPath-Queries.htm

Checkboxes in any Cell in a ListView

2010-05-26T09:25:00.001-07:00

The built-in Checkbox functionality for ListViews will put a checkbox at the beginning of each row. I only needed to put the check box at the beginning of certain rows. The following posting show a simply way to achieve this requirement. I did not use this method exactly as it is shown, but it was definitely a good start:

http://bytes.com/topic/visual-basic-net/insights/880195-putting-checkboxes-any-cell-listview

DiffMerge - Tool to Compare and Merge Files

2010-05-13T13:55:00.000-07:00

A free tool to compare and Merge files and folders:

http://www.sourcegear.com/diffmerge/downloads.html

VB.NET and C# Comparison

2010-04-24T08:38:00.000-07:00

Great posting that compares VB.NET and C#:

http://www.harding.edu/fmccown/vbnet_csharp_comparison.html

Sorting Collections (Generic.List)

2010-04-23T12:26:00.001-07:00

Here is a simple example for sorting collections (such as a Generic.List) based on particular attributes in the objects:

http://stackoverflow.com/questions/438715/how-sort-a-system-collections-generic-list-in-vb-net

Here is another:

http://www.codedigest.com/Articles/CSHARP/84_Sorting_in_Generic_List.aspx

Serializing Objects in .NET as XML or Binary

2010-04-23T06:54:00.000-07:00

This posting provides a good summary of serializing .NET Objects as XML or Binary:

http://devcity.net/Articles/113/1/dotnet_serialization.aspx

Rectangle Structure

2010-03-31T06:16:00.000-07:00

Here is a pretty good link that shows all of the different results using the different method from the Rectangle class such as Union, Intersection, Inflate, etc.:

http://www.java2s.com/Tutorial/VB/0300__2D-Graphics/CreateRectangleFromSizeAndPoint.htm

Simple XOR String Encryption

2010-03-02T11:43:00.000-08:00

Here is a posting I found on how to Encrypt Strings with an XOR operation:

http://www.eggheadcafe.com/tutorials/aspnet/8b53894c-a889-4914-8c46-122980cc44ae/simple-xor-encryption.aspx

Memory Mapped Files in .NET

2010-02-19T11:32:00.001-08:00

Here is a link to info on using Memory Mapped Files in .NET:

http://weblogs.asp.net/gunnarpeipman/archive/2009/06/21/net-framework-4-0-using-memory-mapped-files.aspx

Setting the WCF MaxBufferSize, MaxReceiveMessageSize, and MaxArrayLength in Code instead of App.config

2010-01-15T09:44:00.000-08:00

While the concept of using the app.config file for configuring the many WCF parameters is a nice idea. I sometime like setting the values in code. The most common one for me are MaxBufferSize, MaxReceiveMessageSize, and maxArrayLength because they are usually too small by default for most of my applications. Below I showthe app.config file with these parameters set and then how you can set the same parameters with code in C# and VB.NET.

app.config

VB.NET


' Increase binding max sizes so that the image can be retrieved
If TypeOf pltSvr.Endpoint.Binding Is ServiceModel.BasicHttpBinding Then
  Dim binding As ServiceModel.BasicHttpBinding = _
          CType(pltSvr.Endpoint.Binding, ServiceModel.BasicHttpBinding)
  Dim max As Integer = 5000000 ' around 5M size allowed
  binding.MaxReceivedMessageSize = max
  binding.MaxBufferSize = max
  binding.ReaderQuotas.MaxArrayLength = max
End If


// Increase binding max sizes so that the image can be retrieved
if (pltSvr.Endpoint.Binding is System.ServiceModel.BasicHttpBinding)
{
   System.ServiceModel.BasicHttpBinding binding =
        (System.ServiceModel.BasicHttpBinding)pltSvr.Endpoint.Binding;

   int max = 5000000;  // around 5M
   binding.MaxReceivedMessageSize = max;
   binding.MaxBufferSize = max;
   binding.ReaderQuotas.MaxArrayLength = max;
}

RegCap.exe Unhandled Exception with Deployment Apps

2009-12-07T08:00:00.000-08:00

If you have Deployment Projects in Visual Studio 2008 (maybe 2005 as well), and your app to deploy uses Make Assembly COM-Visible, RegCap.exe will crash when building the deployment project on Windows 7 (maybe on Vista as well).

The work-around appears to be running Visual Studio in XP Compatibility mode.

Here is some more info:

https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=466157&wa=wsignin1.0

Get the User's Temporary Directory in .NET

2009-11-11T06:51:00.000-08:00

System.IO.Path.GetTempPath()

or

Environment.GetEnvironmentVariable("temp")

How to find Regasm.exe and use it in a .Bat file

2009-10-27T09:20:00.000-07:00

I need to use RegAsm.exe to register several assemblies in a .bat file; however, since RegAsm.exe is not in the system path, it is difficult to just use like Regsvr32 which is always in the system path. I suppose the reason for this is that there can be multiple .NET Frameworks installed and you need to use the correct one.

You can use the WINDIR enviroment variable to get the root of the path. It will probably be something like:

C:\WINDOWS

You then need to add "\Microsft.NET\Framework\" to the path, and finally the path to the specific .NET Framework you are using:

SET fwpath="%windir%\Microsoft.NET\Framework\v2.0.50727"

%fwpath%\regasm.exe app.dll

How to pass TARGETDIR with CustomActionData and not get an Error

2009-10-27T09:08:00.000-07:00

Maybe it is just me, but it seems like everything I need to do with an MSI setup is never as easy as it should be. Here is just an other example.

I need to pass the Target Directory for the installation to the InstallClass that I am using in the MSI Custom Actions (I have to do this because of other things in the MSI that don't work like they should). However, when I define the CustomActionData as:

/targetPath=[TARGETDIR]

or

/targetPath="[TARGETDIR]"

I get the following error:

Error 1001. Exception occurred while initializing the Installation:System.IO.FileNotFoundException

The solution I have found is to say this:

/targetPath="[TARGETDIR]\"

I found this info from the following post:

http://www.dotnet247.com/247reference/msgs/35/179584.aspx

I later found the Microsoft documentation on solving the problem:

http://msdn.microsoft.com/en-us/library/2w2fhwzz(VS.71).aspx

Import an Excel File with VB.NET

2009-10-22T14:14:00.000-07:00

Here is a simple solution for importing an Excel file into VB.NET using an OleDbConnection:

http://www.experts-exchange.com/Programming/Languages/.NET/Visual_CSharp/Q_22487951.html

Some Good Examples of MemoryStream in C#

2009-09-16T14:49:00.000-07:00

Here are several good examples of using MemoryStream in C#:

http://www.java2s.com/Code/CSharp/File-Stream/CreateaMemoryStream.htm

Formatting DateTime in C#

2009-09-16T09:28:00.001-07:00

Here is an excellent list of the C# Formatting specifications for the DateTime type. The VB.NET formatting could easily be derived from this post as well:

http://www.csharp-examples.net/string-format-datetime/

How to Save a Bitmap as a 1BPP (bitonal) TIFF File in .NET

2009-09-14T20:36:00.000-07:00

If you try to use the EncoderValue.CompressionCCITT4 value to save a Bitmap out as a 1 BPP Tiff file, you will get an error "Invalid Parameter Value". It turns out that .NET can't go from an RGB to a Bitonal image with the Save method on a Bitmap (no matter how you set the encoder parameters). The following posting by Michael McCloskey solves the problem:

http://www.codeproject.com/KB/GDI-plus/BitonalImageConverter.aspx?msg=2020403

Easy to use and runs quickly.

My Trials and Tribulations getting a WCF Service running on 64 bit Windows Server 2008 with 32 bit Native Dlls

2009-09-03T11:11:00.000-07:00

My WCF Service uses a native DLL written in C++. This native Dll can be 32 bit or 64 bit. The 32 bit version relies on other 3rd party Dlls that are not available in 64 bit. And the 64 bit version is the same thing without the 3rd party dependencies.

1. IIS 7 is easy enough to work in 32 bit or 64 bit mode (on a 64 bit Windows Server 2008 server). By default, the application pool is 64 bit, but you can create another application pool for 32 bit applications or change the default application pool to 32 bit by using the “Enable 32-bit Applications” switch under Set Application Pool Defaults. Then on the Advanced Setting page for your WCF Services Virtual Directory, you can select the Application Pool to use. More Info: http://blogs.msdn.com/rakkimk/archive/2007/11/03/iis7-running-32-bit-and-64-bit-asp-net-versions-at-the-same-time-on-different-worker-processes.aspx

2. The \Windows\System32 directory is for 64 bit files on a 64 Bit OS. And SysWow64 contains the 32 bit files. (Windows on Windows 64 bit). Confusing, but once you know, you know.

3. Getting a 32 bit app using MFC with shared DLLs running on a 64 bit OS can give you a funny error: “The application has failed to start because its side-by-side configuration is incorrect”. The 64 bit OS doesn’t get the standard 32 bit MFC Runtime dlls installed. So you can deliver the 32 bit dependencies or just recompile the DLL using MFC in a Static Library. Easy to fix either way, but the error message is not so obvious. More Info: http://www.eggheadcafe.com/conversation.aspx?messageid=31209382&threadid=31189019

4. The WCF Service always runs fine on the development machine. Deploying it to a real IIS server then has various difficulties to overcome. Mostly, the problem is with security and permissions. If you get: “The caller was not authenticated by the service.” You can possibly just change the binding from wsHttpBinding to basicHttpBinding in the web.config file. Here is more discussion on the issue: http://stackoverflow.com/questions/284538/wcf-error-the-caller-was-not-authenticated-by-the-service

Simple Way to tell if your .NET app is running in 32bit or 64bit Mode

2009-09-03T08:03:00.001-07:00

Here is a quick and easy was to tell if your .NET app is running in 32 bit or 64 bit mode:

C#


bool is64bit = IntPtr.Size == 8;

VB.NET


Dim is64bit As Boolean = IntPtr.Size = 8

More information on from:

http://channel9.msdn.com/forums/Coffeehouse/465445-How-can-I-tell-if-my-NET-application-is-running-in-64bit-on-the-64bit-server/

Problems with Native DLLs, DllImport, and ASP.NET

2009-09-02T13:29:00.000-07:00

I have long had a problem when using ASP.NET where my native Dlls can't be found when the .NET Assembly calls a function from the native Dll. The only solution I have been able to find is to put the native DLLs in a directory that is in the system PATH (or in a directory that is already in the PATH like Windows\system32). I have searched the internet many times and finally found a posting that explains why even if there doesn't appear to be a good solution:

http://bytes.com/topic/c-sharp/answers/843777-asp-net-dllimport

Stephen Cheng explains that the .NET assemblies are copied to a ASP.NET temporary directory before they are are run. Since the .NET assemblies really don't know anything about the native .DLLs, the native DLLs don't get copied. When the .NET assembly tries to use a method in the native DLL, it is not there and you get the error message:

"An exception of type 'System.EntryPointNotFoundException' occurred in xxx.DLL but was not handled in user code Additional information: Unable to find an entry point named 'xxxx' in DLL '.\xxx.dll'."

It doesn't matter that the Native dll is in your ASP.NET project's bin directory, because that is not where it is run from.

The solutions given are to use LoadLibrary to get the dll loaded into memory, but you have to know where it is. You can turn the shadowCopyBinAssemblies off in the web.config file, but this has problems. And finally, you can add the location of the native dll to the system PATH.

If any one knows of a better solution, please post a comment.

Posting Code in Blogger

2009-08-30T13:20:00.001-07:00

This posting is off topic too, but I have finally found some good instructions on posting code samples on Blogger. See this post for details:

http://abhisanoujam.blogspot.com/2008/12/blogger-syntax-highlighting.html

Restarting IIS from the Command-Line

2009-08-27T10:05:00.000-07:00

This posting is a little off topic, but I always forget the command-line command to restart IIS. It is simply: iisreset

Here is more info at:

http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/003ed2fe-6339-4919-b577-6aa965994a9b.mspx?mfr=true

How to tell in VB.NET or C# if the Ctrl or Shift Key are being pressed

2009-08-04T14:19:00.000-07:00

Sometimes you may need to know if the Ctrl or Shift key is being pressed by checking its state instead of using a key event. Also, most solutions to this problem involve some pinvoking and the win32api GetKeyState, but it turns out to be very simple as this posting describes:

http://predicatet.blogspot.com/2008/04/how-to-detect-if-shift-or-control-key.html

Here is the gist:

if (Control.ModifierKeys == Keys.Control)
{

}

Getting Started Building HTML Help Files (.CHM) from Visual Studio's XML Documentation

2009-07-22T16:35:00.001-07:00

If you want to build HTML Help files (.CHM) from the XML Documentation embedded in your .NET code, here is a good post on how to get started:

http://saftsack.fs.uni-bayreuth.de/~dun3/archives/integrate-xml-code-comments-into-visual-studio-20052008-using-sandcastle-and-html-help-20/150.html

Here is some more information after you get going:

http://www.codeproject.com/KB/XML/csharpcodedocumentation.aspx

Here is even more good info on the XML Documentation Syntax from Alan Dean:

http://thoughtpad.net/alan-dean/cs-xml-documentation.html

Making your .CHM FIles (HTML Help) use a larger Font

2009-07-22T15:46:00.000-07:00

This post is a little off topic, but this tip is worth a little more press.

If you can't read a .CHM file (HTML Help file) because the font is just too small, you can make it readable again (Thanks Garth Jones).

http://smsug.ca/blogs/garth_jones/archive/2008/10/20/tip-of-the-day.aspx

Options/Internet Options/Accessibility -> Ignore Fonts Sizes on specified Web pages

Good Example of using IDisposable with File Streams

2009-07-20T14:55:00.001-07:00

Here is a simple, yet good example of how to implement IDisposable when dealing with File Streams:

http://www.blackwasp.co.uk/IDisposable.aspx

Here is a similar example with some discussion, but the first link is probably better:

http://stackoverflow.com/questions/1136210/am-i-implementing-idisposable-correctly

Creating Custom Dictionary for Code Analysis in Visual Studio

2009-07-20T14:34:00.000-07:00

Here is a good description of how to add your own custom words to the spelling dictionary used by Visual Studio's Code Analysis Naming rules (also known as FXCop):

http://duncanjasmith.blogspot.com/2008/07/creating-custom-dictionary-for-code.html

Getting Started with Virtual Earth/Bing Maps

2009-07-17T17:20:00.000-07:00

Here is a great video on how to get going with Virtual Earth (now Bing Maps).

This video gets you through all of the problems that show up that the documentation fails to cover.

http://www.liveside.net/developer/archive/2008/09/29/video-getting-started-with-the-virtual-earth-web-service.aspx

Setting the Exit Code when exiting a VB.NET or C# Console App

2009-07-06T11:26:00.000-07:00

To set the Exit Code (ErrorLevel) when a VB.NET or C# Console Application exits, use the following (or similar):

Dim retCode as Integer = 0
.
.
.
System.Environment.Exit( retCode)

The call to Exit will end the application.

Implementing a SQL-like 'LIKE' Comparison in VB.NET

2009-07-02T17:33:00.000-07:00

I searched the net for some time to find an easy way to implement the logic in the SQL LIKE in a VB.NET function. There were many over simplified examples. Then I found this elegant solution using regular expressions (regex). The original is found here in C#:

http://bytes.com/groups/net-c/253519-using-regex-create-sqls-like-like-function

I have provided a VB.Net version below:

Public Function IsSqlLikeMatch(ByVal input As String, ByVal pattern As String) As Boolean

' Turn "off" all regular expression related syntax in
' the pattern string.

pattern = Regex.Escape(pattern)

' Replace the SQL LIKE wildcard metacharacters with the
' equivalent regular expression metacharacters.

pattern = pattern.Replace("%", ".*?").Replace("_", ".")

' The previous call to Regex.Escape actually turned off
' too many metacharacters, i.e. those which are recognized by
' both the regular expression engine and the SQL LIKE
' statement ([...] and [^...]). Those metacharacters have
' to be manually unescaped here.

pattern = pattern.Replace("\[", "[").Replace("\]", "]").Replace("\^", "^")

Return Regex.IsMatch(input, pattern)

End Function

Converting code between VB.NET and C# using SharpDevelop

2009-06-25T11:08:00.000-07:00

While I really love the online VB.NET to C# and C# to VB.NET code converters provided by developerFusion, I have also found the open source SharpDevelop application to be a very good tool for converting .NET code from one flavor to another. It is especially good at converting whole projects or larger amounts of code. I think it is worthy a post:

http://www.icsharpcode.net/OpenSource/SD/

Code Conversion Features:

http://community.sharpdevelop.net/blogs/mattward/articles/FeatureTourCodeConversion.aspx

Code Conversion is one very small part of SharpDevelop. The rest is worth a look too!

Converting a Byte Array to a String in VB.NET

2009-06-05T10:05:00.000-07:00

Here is one way to convert a byte array to a String in VB.NET:

Dim bArray() As Byte = {65, 66, 67, 68, 69}
Dim str As String
str = System.Text.Encoding.ASCII.GetString(bArray)

More examples of converting Byte Arrays to Strings and vice versa in VB.NET and C# can be found here:

http://www.chilkatsoft.com/faq/DotNetStrToBytes.html

Getting Application Path for a Console App

2009-06-05T10:02:00.001-07:00

In a previous post, I gave examples of getting the Application Path for a Windows Form app and a Windows Mobile app. Getting the Application Path for a Console app is similar to getting one for the Windows Mobile app:

Dim appPath As String = _
System.IO.Path.GetDirectoryName( _
System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase)

TechEd 2009 in Los Angeles

2009-05-18T10:08:00.000-07:00

This year the TechEd Developers Conference was merged with the TechEd IT conference and happened last week in Los Angeles. While there were significantly fewer Developer oriented sessions, it was interesting to sit in some of the IT sessions. With around 700 sessions to choose from and only about 20 you can actually attend, the need to be particular about what you want to learn becomes very important. I heavily weighted my track with “Mobile”, but I also checked out SQL Server’s Spatial capabilities, and the future directions of the development environments and programming languages.

The push, I mean focus, this year was definitely the yet to be released Windows 7 and Windows Server 2008 R2, followed by a healthy dose of Virtualization in the form of Hyper-V and Windows Virtual PC.

I did have an opportunity to run my apps on a beta copy of Windows 7 at the “Bring Your Own App Lab.” There were a few glitchy things with reading some values out of the registry, but overall I was very pleased with how my apps worked the first time on Windows 7. I have already checked off a lot of grief on my to-do list from this experience. The free booze they were passing out was not even necessary to favorably color my opinion of Windows 7.

The focus last year was definitely LINQ, which seems to have been toned down now to is actual value. WPF and Silverlight, looked cool to try, but now they look usable. Microsoft’s creation of tools to help spawn the development of new programming languages is supposed to bring about an explosion in new languages. I along with everyone else in the Polyglot Programmer session cringed at the idea of having to learn dozens of new languages, but like LINQ, this idea may fade into a manageable and productive tool in our programming arsenal. I was hoping to see Windows Workflow (WF) be a hotter topic than it apparently is, but it may take a few iterations before it catches on.

I was pretty pleased with TechEd 2009. I will continue to process the information for a while.

Scaling one Rectangle to fit in Another Rectangle

2009-05-05T17:26:00.001-07:00

Here is a great posting that shows several approaches to scaling one rectangle to fit inside of another:

http://www.vbdotnetforums.com/graphics-gdi/33829-scale-rectangle-fit-another.html

GetComputerName equivalent in VB.NET and C#

2009-04-13T08:36:00.000-07:00

The Win32Api GetComputerName has a simpler equivalent in the .NET world:

Dim compName as String = Environment.MachineName.ToString

Getting the Version of an OleDB Provider

2009-04-08T10:25:00.000-07:00

There may a much simpler way of determining the version of an OleDb provider (like OraOledb.Oracle.1) than I have shown below, but I have yet to find one.

The OleDbConnection object will tell you the version fo the Server through its ServerVersion property:

Dim myConn As New OleDbConnection(g_gtech.GetConnectionString)
myConn.Open()
Dim versionStr as String = myConn.ServerVersion.ToString
myConn.Dispose()

But, I often want to the know the version of the Provider it self. The only way I have found to do this is to sift through the registry and read the ProductVersion off the provider dll itself.

For example:

Dim versionStr as String = _
GetProviderVersion("OraOleDb.Oracle.1")

Here is the supporting code:

Public Function GetProviderVersion(ByVal providerName As String) As String

Try

Dim clsid As String = GetRegistryValue(Registry.LocalMachine, _
"SOFTWARE\Classes\" + providerName + "\clsid", "")

If clsid.Trim = "" Then Return "Not Installed"

Dim path As String = _
GetRegistryValue(Registry.LocalMachine, "SOFTWARE\Classes\CLSID\" + clsid + "\InprocServer32", "")

Dim Info As FileVersionInfo
Info = FileVersionInfo.GetVersionInfo(path)
Return Info.ProductVersion.ToString

Catch ex As Exception

Return "Unable to get Version"

End Try

End Function

Public Function GetRegistryValue(ByVal regKey As RegistryKey, _
ByVal subKey As String, ByVal valueName As String) As String

Dim value As String = ""
Dim registryKey As RegistryKey = regKey
Dim registrySubKey As RegistryKey
registrySubKey = registryKey.OpenSubKey(subKey)
If registrySubKey IsNot Nothing Then
Try
value = registrySubKey.GetValue(valueName).ToString
Catch ex As Exception
value = ""
End Try
registrySubKey.Close()
End If
Return value
End Function

If there is a simple or more elegant way to find the Provider version, please comment.

Setting the DateTimePicker to a Blank Value

2009-03-27T13:15:00.000-07:00

I wanted to use the DateTimePicker control on a data entry form; however, it always has to be set to a value. I did not want to set the date value to Now or some other preset value because it is not clear to the user that the value needs to be set. I found several solutions to this problem, but the one below appears to work and is easy to use.

Initialize the DateTimePicker control to a blank value by setting the Format property to Custom and the CustomFormat property to a space (" "):

DateTimePickerConstDate.CustomFormat = " "
DateTimePickerConstDate.Format = DateTimePickerFormat.Custom

Then, when the value changes, change the Format property back to its original value (or define a usable Custom Format:

Private Sub DateTimePickerConstDate_ValueChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DateTimePickerConstDate.ValueChanged

DateTimePickerConstDate.Format = DateTimePickerFormat.Short

End Sub

For more information on this solution and other approaches, see the following:

http://social.msdn.microsoft.com/Forums/en-US/netfxcompact/thread/46b2a370-72ec-485c-9361-bfa505bb6863/

Sorting a VarChar Attribute as a Number in a SQL Statement

2009-03-22T07:57:00.000-07:00

This post is not particularly .NET, but I am posting it anyway.

I was needing to sort the results of a SQL statements by a Priority attribute (which has the values 1 to 10). Unfortunately, the Priority attribute is defined as VarChar, so 10 always follows 1 when you do an ORDER BY Priority.

There are many solutions to this problem, but this simplest (although not the more readily obvious, and maybe not the most efficient) is this:

SELECT * FROM Data_Table ORDER BY Len(Priority), Priority ASC

Another approach is:

SELECT * FROM Data_Table ORDER BY RIGHT('0000' + RTRIM(LTRIM(Priority)), 4)

There are other approaches in the posts where I found this solution:

http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=81901

http://www.eggheadcafe.com/conversation.aspx?messageid=29907381&threadid=29907381

Appending a File with StreamWriter

2009-02-12T14:15:00.000-08:00

The StreamWriter class has an Append flag that can be set to append to the file:

Dim outfile As New StreamWriter(filename, True)

The are other overloaded versions with the append flag as well.

Utility: Process Explorer

2008-12-17T12:41:00.000-08:00

This article in PC Magazine discusses a utility called the Process Explorer (free from Sysinternals):

http://www.pcmag.com/article2/0,2817,2332918,00.asp

The utility can be downloaded from:

http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx

This utility is like Task Manager's Process Viewer, only it tells much more information that can be used to diagnose problems.

How to determine the .NET Compact Framework Version on the Device

2008-11-18T15:16:00.000-08:00

Here is the best posting I have found to determine the version of the .NET Compact Framework on the device:

http://www.byteswired.com/2007/09/27/how-to-determine-compactframework-version/

The summary is that you look at the registry key:

HKLM\SOFTWARE\Microsoft\.NetCompactFramework

Determine OS version with .NET Compact Framework

2008-11-11T14:51:00.000-08:00

If you are running a Device application and want to know (in the code) which platform you are running on (it could be CE.NET or Windows Mobile or various versions of each), then you can use:

Environment.OSVersion.Platform

For much more information and several examples, see:

http://www.christec.co.nz/blog/archives/77

Selecting all Items in a ListBox in VB.NET

2008-11-07T12:38:00.000-08:00

It seems to me like there should be a method that would select or deselect all items in a listbox, but there is not. Here is a simple sub to accomplish this task:

Public Sub SelectAllListBoxItems(ByVal lv As ListBox, ByVal selected As Boolean)

For i As Integer = 0 To lv.Items.Count - 1

ListBoxValidations.SetSelected(i, selected)

Next

End Sub

Parsing text Syntax Highlighting in a Rich Text Box

2008-10-25T14:13:00.000-07:00

Here is an interesting posting on how to format text in a Rich Text Box control so that it does Syntax Highlighing:

http://www.c-sharpcorner.com/uploadfile/duncanharris/syntaxhighlightinrichtextboxp112012005050840am/syntaxhighlightinrichtextboxp1.aspx

Great Info on Working with Text in .NET

2008-10-24T14:42:00.000-07:00

The following link shows how to Align Text, Clip Text, Wrap Text, Transform Text, and Shade Text in .NET:

http://www.devx.com/dotnet/Article/33464/1954

Converting a TrueType Font Character into a Bitmap

2008-10-24T10:48:00.000-07:00

Here is an excellent article on creating a bitmap from a TrueType Font Character. If you want to create a symbol selection dialog with a ListView, these routines can generate the Bitmap image for the listview items.

http://www.codeproject.com/KB/GDI-plus/TTF_to_bitmap_convert.aspx

This article did more than I needed. I only wanted to create the images for a ListView for all of the characters in a TrueType font. I have boiled down the code from the above article to the following:

Private Sub UpdateSymbolList(fontName as String)

ListView1.Items.Clear()

For i As Integer = 0 To 255

Dim bm As Bitmap = ConvertChar(fontName, i, Color.Blue, 32, 32, 20)
ImageList1.Images.Add(i.ToString, bm)

Next

ListView1.LargeImageList = ImageList1
ListView1.SmallImageList = ImageList1

For i As Integer = 0 To 255
Dim lvi As New ListViewItem
lvi.Text = i.ToString
lvi.ImageKey = i.ToString
ListView1.Items.Add(lvi)
Next

End Sub

Public Shared Function ConvertChar(ByVal fontName As String, _
ByVal charCode As Integer, _
ByVal color As Color, _
ByVal bitmapWidth As Integer, _
ByVal bitmapHeight As Integer, _
ByVal characterSize As Single) As Bitmap

Dim charToDraw As Char = Chr(charCode)
Dim bitmap As New Bitmap(bitmapWidth, bitmapHeight)
Dim g As Graphics = Graphics.FromImage(bitmap)
Dim fnt As Font = New Font(fontName, characterSize, FontStyle.Regular)
Dim textFormat As New StringFormat()

textFormat.Alignment = StringAlignment.Center
textFormat.LineAlignment = StringAlignment.Center

g.DrawString(charToDraw.ToString, fnt, New SolidBrush(color), New RectangleF(0, 1, bitmapWidth, bitmapHeight), textFormat)

g.DrawRectangle(New Pen(Drawing.Color.Black, 1), New Rectangle(0, 0, bitmapWidth - 1, bitmapHeight - 1))

Return bitmap

End Function

Option Strict On causes Disallows Late Binding Error when getting Variant Array from a COM Object

2008-10-21T12:55:00.001-07:00

I have several ActiveX controls that I use with .NET. Generally, there are not too many problems using them with .NET, but I have come across one error that was difficult (for me) to solve.

Since the ActiveX controls were originally written for VB6, they return Variants and arrays are returned as Variants of Variants. This is all fine because .NET has an Object type to work with the variants. As a rule, however, I use Option Strict On because if you don't use this option, Dotfuscator will really cause problems without letting you know in advance. But the catch is that with Option Strict on, you cannot do something like the following:

Dim varArray as Object
Dim count as Integer

SomeComObject.GetList( varArray, count )

For i as Integer = 0 to count - 1

Debug.WriteLine( varArray(i).ToString )

Next

varArray will return list of integers, but as a Variant Array of Variant Integer values.

The code above will not work with Option Strict On because the varArray(i) is late bound and this is not allowed. My first though was to try:

Dim val as integer = CType( varArray(i), Integer)

The above code does not work or any similar cast.

The only solution I have discovered (and there are probably others) is to cast the Variant array as an Object array like:

Dim vArray() as Object = CType( varArray, Object())

Then the vArray is a Object Array and can be further cast to other types without catching on the Option Strict On. For example:

Dim catList As Object = Nothing
Dim offsetList As Object = Nothing
Dim filterList As Object = Nothing

While viewObj.GetElementsInRangeFetch(1000, catList, offsetList, filterList, blockCount)

Dim cList() As Object = CType(catList, Object())
Dim oList() As Object = CType(offsetList, Object())
Dim fList() As Object = CType(filterList, Object())

For j As Integer = 0 To blockCount - 1
ProcessFeature(CInt(cList(j)), CInt(oList(j)), CInt(fList(j)))
Next

catList = Nothing
offsetList = Nothing
filterList = Nothing

End While

This may not be the cleanest solution, but it does work and allow the Option Strict setting to be left on.

Option Strict On causes Disallows Late Binding Error when getting Variant Array from a COM Object

2008-10-21T12:55:00.000-07:00

Auto Fit Columns in a DataGridView

2008-10-19T14:13:00.000-07:00

I have posted a function to auto-fit the columns in a ListView before. However, when I wanted to do the same thing for a DataGridView, the task is a little different (yet easier):

DataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells

Basic Registry Operations with VB.NET

2008-10-16T15:29:00.000-07:00

Reading and Writing to the Registry in VB.NET is fairly simple, especially when compared to using C++. However, it can still be a little difficult to get going. Here are 3 functions to perform the basic Registry operations: Read, Write, and Delete.

Examples Using the Functions:

Dim value As String = _
GetRegistryValue(Registry.LocalMachine, _
"SOFTWARE\CompanyName\ApplicationName", "License")

SetRegistryValue(Registry.LocalMachine, _
"SOFTWARE\CompanyName\ApplicationName", _
"License", "value")

DeleteRegistryValue(Registry.LocalMachine, _
"SOFTWARE\CompanyName\ApplicationName", "License")

Read a Registry Value

Public Function GetRegistryValue(ByVal regKey As RegistryKey, _
ByVal subKey As String, ByVal valueName As String) As String

Dim value As String = ""
Dim registryKey As RegistryKey = regKey
Dim registrySubKey As RegistryKey

registrySubKey = registryKey.OpenSubKey(subKey)

If registrySubKey IsNot Nothing Then
Try
value = registrySubKey.GetValue(valueName).ToString
Catch ex As Exception
value = ""
End Try
registrySubKey.Close()
End If

Return value

End Function

Write a Registry Value

Public Function SetRegistryValue(ByVal regKey As RegistryKey, _
ByVal subKey As String, ByVal valueName As String, ByVal value As String) As Boolean

Dim registryKey As RegistryKey = regKey
Dim registrySubKey As RegistryKey

registrySubKey = registryKey.OpenSubKey(subKey, True)

If registrySubKey Is Nothing Then
registrySubKey = registryKey.CreateSubKey(subKey, RegistryKeyPermissionCheck.ReadWriteSubTree)
End If

If registrySubKey IsNot Nothing Then
registrySubKey.SetValue(valueName, value)
registrySubKey.Close()
Return True
End If

Return False

End Function

Delete a Registry Value

Public Function DeleteRegistryValue(ByVal regKey As RegistryKey, _
ByVal subKey As String, ByVal valueName As String) As Boolean

Dim value As String = ""
Dim registryKey As RegistryKey = regKey
Dim registrySubKey As RegistryKey

registrySubKey = registryKey.OpenSubKey(subKey, True)

If registrySubKey IsNot Nothing Then
Dim retValue As Boolean = True
Try
registrySubKey.DeleteValue(valueName)
Catch ex As Exception
retValue = False
End Try
registrySubKey.Close()
Return retValue
End If

Return False

End Function

FTP Upload and Download in VB.NET and C#

2008-10-03T14:07:00.000-07:00

The following site has C# code to upload and download a file via FTP in C#:

http://www.codeguru.com/csharp/csharp/cs_internet/desktopapplications/article.php/c13163

You can take the C# code and paste into the converter at the following web site to get VB.NET:

http://www.developerfusion.com/tools/convert/csharp-to-vb/

Getting Windows Mobile Owner Name and Device Name

2008-10-02T16:00:00.000-07:00

It is sometimes useful to get the Owner Name and/or the Device Name of the Windows Mobile device. If you are wanting a Device Id, then see this posting.

There are different ways to get the Owner Name and Device Name:

For Owner Name, add the following reference to your project:

Microsoft.WindowsMobileMicrosoft.WindowsMobile.Status

Then in your code:

Imports Microsoft.WindowsMobile.Status
.
.
.
MessageBox.Show(SystemState.OwnerName)

More info at:

http://www.c-sharpcorner.com/Forums/ShowMessages.aspx?ThreadID=46306

To get the Device Name (which is what you find under Start/Settings/System Tab/About), you simply have to say:

MessageBox.Show(System.Net.Dns.GetHostName())

For more Info:

http://msdn.microsoft.com/en-us/library/system.net.dns.gethostname.aspx

Unresolved Externals when using POOM in VC++

2008-09-24T02:26:00.000-07:00

I found several postings when searching for a solution to compiling a POOM app that errors out with Unresolved External Symbol CLSID_Application and IID_IPOutlookApp. Only one of the solutions I found worked for me using Visual Studio 2008 C++:

http://www.tech-archive.net/Archive/PocketPC/microsoft.public.pocketpc.developer/2006-03/msg00236.html

The trick is to use:

#include "initguid.h"
#include "pimstore.h"

at the begining of the .cpp file. The initguid.h is the item that fixes the problem.

Incrementing FileVersion for VC++

2008-09-06T16:37:00.000-07:00

In a recent posting, I talked about solutions to incrementing the FileVersion in Visual Studio .NET for VB.NET and C# project. This need was motivated by the changes in VS2008 that requires a FileVersion to be changed before the Windows Installer will replace a file.

Some of my projects have Native DLLs that are compiled in VS 2008's VC++ compiler. These files has the same problem with the installer, yet the previous solution (http://dotnetref.blogspot.com/2008/09/auto-incrementing-file-version-in.html) did not address.

I found this very handy Add-In that works well with VS2008 (and previous versions) that will increment the FileVersion (Product Version, etc.) in the VC++ projects resource file.

http://www.codeguru.com/cpp/v-s/devstudio_macros/visualstudionet/article.php/c14981

Visual Studio 2008 Setup Project always requiring .NET Framework 3.5 even when 2.0 is Targeted

2008-09-05T08:56:00.000-07:00

I am slowly upgrading my projects from VS2005 to VS2008. I had a puzzling problem with the Setup Projects always requiring the .NET Framework 3.5 even when the Setup Project is targeted to 2.0 and the application it is delivering is using .NET Framework 2.0.

There are several posting on the the internet about solving this problem. It basically requires you to go to View/Editor/Launch Condition and change the .NET Framework to the version you desire. The Project properties for your setup project are a bit misleading when they have no affect on this problem.

Read these posting for more detailed explanations:

http://impressionsoft.blogspot.com/2008/03/visual-studio-2008-setup-project-and.html

http://blogs.msdn.com/cschotte/archive/2007/08/15/vs2008-launch-conditions-and-prerequisites.aspx

Auto-Incrementing the File Version in Visual Studio 2005 and 2008

2008-09-04T14:31:00.000-07:00

*** Update - Since I made this post, I have found another tool that is simpler to use and also work with VS2010. See this http://autobuildversion.codeplex.com/

If this doesn't work for you, then you may with to view the info below:

The Setup and Deployment (Windows Installer) has a significant change between VS2005 and VS2008. In VS2008, a file will not be updated by the installer if the File Version has not changed. This pretty much breaks all of the VS2005 Installations I have created. There are various reasons for this, and I will let you read for yourself:

http://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.vstudio.general&tid=c4c56abf-9bde-45ed-8737-90cf90514d89&cat=&lang=&cr=&sloc=&p=1

The solution to the problem is to increment the File Version (under Project Properties/Assembly Information) between Setup (.msi) builds. So, before every setup you create, you have to go manually update the File Version so the setup will update the file. Before, you just had to update the Version property in the Installer Project (and let it update the Product Code); you still have to do this (which is probably acceptable). I thought there must be someway to automatically increment the File Version since this change to the Installer breaks all of my setups; however, there is not (that I can find anyway). The only workable solution I have found is to use a BuildTask that updates the AssemblyInfo.vb (or AssemblyInfo.cs) before each build is made. This solution is a really complicated for something that was a checkbox in VB6 (as someone pointed out).

Here is the solution I tried and it does work:

http://www.codeproject.com/KB/dotnet/Auto_Increment_Version.aspx

Here is a similar solution:

http://weblogs.asp.net/bradleyb/archive/2005/12/02/432150.aspx

Launch Internet Explorer or Default Browser from VB.NET (or C#)

2008-09-03T13:56:00.000-07:00

I found several ways to launch IE from VB.NET, but the following approach appears to be the simplest:

Process.Start("IExplore.exe", "http://dotnetref.blogspot.com")

More information at:

http://bytes.com/forum/thread413370.html

If you want to launch the default browser (such as Firefox), it may be easiest to just say the following:

Process.Start("http://dotnetref.blogspot.com")

and let the Shell do the work of deciding th default browser.

For more info on this approach:

http://www.vbforums.com/showthread.php?t=323257

The C# approach is not any different, just use the approprate syntax.

Getting a Device ID using the Compact Framework

2008-08-28T10:36:00.000-07:00

Here are a couple of approaches I found for getting a Device ID using the compact framework. Both are lengthy solutions to something that should probably be built into platform.

http://msdn.microsoft.com/en-us/library/ms172516.aspx

http://msdn.microsoft.com/en-us/library/aa446562.aspx

http://blogs.msdn.com/jehance/archive/2004/07/12/181067.aspx

How to do a CDC.Escape() in .NET

2008-08-28T08:11:00.000-07:00

There may be ways around using the old CDC Escape function from MFC, but when you are porting C++ to C#, it is nice to just call the same Win32api functions that you were using before. For printing, I used the Escape function to get information about the printer, but since this method can return a Point structure the PInvoke was more difficult. Here is the code necessary to call the Escape method:

First you need the POINT structure defined in .NET:

[StructLayout(LayoutKind.Sequential)]
public struct POINT
{
public int X;
public int Y;
public POINT(int x, int y)
{
this.X = x;
this.Y = y;
}
}

Then you need the Signature for the Escape method ):

[DllImport("gdi32.dll")]
private static extern int Escape(IntPtr hdc, int nEscape, int cbInput, string lpvInData, IntPtr lpvOutData);

There are also the constants that are sent as the Escape type (I just provide a couple of example that return a Point structure):

private const int GETPRINTINGOFFSET = 13;
private const int GETPHYSPAGESIZE = 12;

Then you can call the method. You can get the Graphics object from various places, but you need the HDc from it regardless:

IntPtr hDC = e.Graphics.GetHdc();
IntPtr pnt;
long stat;
POINT printingOffsetPoint = new POINT(0,0);
pnt = Marshal.AllocHGlobal(Marshal.SizeOf(printingOffsetPoint));
Marshal.StructureToPtr(printingOffsetPoint, pnt, false);
stat = Escape(hDC,GETPRINTINGOFFSET, 0, null, pnt);
printingOffsetPoint = (POINT)Marshal.PtrToStructure(pnt, typeof(POINT));
Marshal.FreeHGlobal(pnt);

POINT physPageSizePoint = new POINT(0, 0);
pnt = Marshal.AllocHGlobal(Marshal.SizeOf(physPageSizePoint));
Marshal.StructureToPtr(physPageSizePoint, pnt, false);
stat = Escape(hDC, GETPHYSPAGESIZE, 0, null, pnt);
physPageSizePoint = (POINT)Marshal.PtrToStructure(pnt, typeof(POINT));
Marshal.FreeHGlobal(pnt);

Using Dock Fill on a Control when you have a Menu and/or Status Bar

2008-08-07T10:13:00.000-07:00

I have long been frustrated in Visual Studio .NET when I try to use a control's Dock property set to Fill and also have a Menu or Status bar on the same form. The Docked control typically fills to the form and is not the right size (not accounting for the size of the Menu or Status bar).

It turns out that there is a very simple (but not very obvious) solution to this problem. Taken from Alex Fr's response to a comment on a similar problem:

"Actually, all you need to do is rightclick the panel and choose "bring to front", the dock layout logic handles each component in order so when it reaches your panel first it doesnt know it has other components that fill up other parts of the container with their docking settings. "

Just make sure the Docked control is in front of the menu and status bar and it works as you would expect.

Seeing what color the .NET Color names actually are

2008-08-03T08:59:00.000-07:00

I found a very useful .NET Color reference at the following web site. If you want to compare AliceBlue, DodgerBlue, and SteelBlue, here is an easy way to do it:

http://www.opinionatedgeek.com/DotNet/Tools/Colors/default.aspx

Setting the Form Icon to an Application Resource in VB.NET

2008-07-30T14:14:00.000-07:00

I have an application with a main form and many dialogs. I want the main form and all of the dialogs to use the same icon in the forms' title bars. So, instead of defining the Icon property on each form, I have created an application resource and added a line of code to each Form_Load method.

First, add an Icon to your Project Resources (Project/Properties then on the Resource tab). Remember the name of the icon resource you create. Mine is AppIcon in this example.

Then for each Form_Load method in the VB.NET app (for the main form and each dialog's form), I add the following:

Me.Icon = My.Resources.AppIcon

There may be even better ways to do this, but this is the simplest I have found so far.

For more information on using resources, see:

http://visualbasic.about.com/od/usingvbnet/a/ResVBNET.htm

Keeping a Nonmodal form on top of App, but not on top of Everything

2008-07-29T14:29:00.000-07:00

It took me a while to figure this one out, but the solution is pretty simple.

I want to keep a nonmodal form on top of my main app form. I have tried using:

Dlg.TopMost = True

in the nonmodal form (Dlg), but this approach keeps the form on top of everything, not just my main app form.

The solution is:

Dlg.Owner = Me ' Me is the main app form
Dlg.TopMost = False

More info can be found at:

http://www.syncfusion.com/faq/windowsforms/faq_c95c.aspx#q975q

Changing a Control's Font Size at Runtime in VB.NET

2008-07-24T09:50:00.000-07:00

If you have a control that is using a font with size 8.25 (which was defined at design-time), then at runtime you want to change it to a different size (such as 12), you cannot simply say:

ctrl.Font.Size = 12 (this will not work - Property Size is Read-Only)

However, you can replace the whole font:

ctrl.Font = new Font(ctrl.Font.FontFamily, 12, ctrl.Font.Style)

For more info and examples in C#, see: http://bytes.com/forum/thread261450.html

Using Brushes with Semi-Transparent Color

2008-06-29T08:50:00.000-07:00

Filling a Rectangle, Ellipse, Shape, etc. with a semi-transparent fill is done by using a SolidBrush with a Alpha value somewhere between solid and transparent.

C#:

Color col = Color.FromArgb(75, 100, 100, 100);
SolidBrush b = new SolidBrush(col);
g.FillRectangle(b, 0, 0, this.Width - 1, this.Height - 1);

VB.NET:

Dim col As Color = Color.FromArgb(75, 100, 100, 100)
Dim b As New SolidBrush(col)
g.FillRectangle(b, 0, 0, Me.Width - 1, Me.Height - 1)

For better examples, go to this link:

http://www.java2s.com/Code/CSharp/2D-Graphics/Filledwiththesemitransparentandtransparentcolor.htm

Disappearing Controls in the Left SplitContainer Panel when using Large Fonts

2008-06-18T15:57:00.000-07:00

I have been experiencing a strange problem that I have finally confirmed as a bug in the .NET Framework 2.0. If you are using a SplitContainter and place controls in your Left panel, then if you anchor those controls to the Right or the Bottom, they will disappear when you run the app on a machine that is using Large Fonts. My controls happen to all be in a group box, but I don't think that matters. The controls disappear because the anchor is setting the height and/or width to 0 and they are not visible. If you can drag the size wide or tall enough, the controls will start to appear, but they scaling is off and the anchor is not working correctly. If using Small Fonts, this problem does not exists.

I found a few other people with the same problem, but no solutions. I found one suggestion to do a Refresh on the Splitter move event, but this did not help me. My solution has been to adjust the size of the controls in the left panel myself and not rely on the anchor. Please post a comment if you have a better solution to this problem.

Setting BackColor to System Colors (like "Control")

2008-06-14T15:33:00.000-07:00

It took a little searching to find out how to set the BackColor or ForeColor property of a control to the predefined colors you gets in the Visual Studio Properties window for BackColor's popup color setting on the System tab. For example, I want to set to the BackColor to the "Control" color.

control.BackColor = Color.FromKnownColor(KnownColor.Control)

I found this on:

http://bytes.com/forum/thread654472.html

TechEd 2008 in Orlando

2008-06-12T07:12:00.000-07:00

The TechEd 2008 Deveveloper’s Conference was in Orlando last week. I have always attended MEDC (Mobile and Embedded Developer’s Conference) before, but it has now been merged into TechEd. I believe that I prefer the more focused content of MEDC, but if my only way to get this information is to go to TechEd, then it is not too bad of an alternative. However, there were only 11 Windows Mobile session at TechEd 2008.

There is always a flavor to a Microsoft conference. I don’t know if this is directed by the powers that be or simply a natural alignment to the new features they are providing (or a combination of both). This year, the flavor definitely tastes of LINQ (Language Integrated Query). LINQ is undeniably an interesting concept that directly integrates SQL-like statement into the language syntax of any .NET language (VB.NET, C#, etc.). What makes this new feature somewhat interesting is that the SQL statements can be applied to data in arrays, enumerable objects, XML, and databases. So, the SQL way of querying a database can now be directly applied to data in your application, not just databases.

It also appears that most of the new language features we get from Visual Studio 2008 are directly related to LINQ: Anonymous Types, Extension Methods, Lambda Expressions, Implicitly typed locals, and Object Initializers. All of these new features were added just to support LINQ. One session on the Visual Studio 2008 IDE revealed that there wasn’t much added to the IDE because all of the developers were working on LINQ. On the downside, while LINQ does run on Windows Mobile, it will only work with your application data and does not work with SQL CE. There are a lot of things in the Compact Framework I would have rather had than a partially implemented version of LINQ.

While just about every session had to work LINQ in somehow, there were a couple of other technologies that were shown off. The Windows Presentation Manager (WPF) has developed a good deal since last year and can really produce some spectacular looking demos. The new support in Visual Studio 2008 for WPF is nice, but really seems to be early in its development. All of the WPF sessions seem to highlight a few points: it has great potential, it’s not here yet, and you will need a graphic designer to properly use it. A common phrase I heard in the session is “I’m not a graphic designer, so my WPF doesn’t look very good.” Nevertheless, I still found the Technology compelling enough to pursue. As an aside, Silverlight, which is an offshoot of WPF, came across as a very immature technology. Maybe it will mature quickly.

The Window Communication Foundation (WCF) was also a popular topic. It is just the extension of Web Services to what it probably should have been in the first place.

The Windows Workflow Foundation (WF, because WWF was already taken), was new to me and looks really interesting. An oversimplified description of it would be a project type in Visual Studio that lets you create a flow chart or diagram of your business logic and then can add the code behind the items in the diagram. The WF demos were compelling, but I have to question how well it really works in the real world. The demos used very simplistic logic. How well WF scales to a real application would be interesting to know. I think time will tell on this technology. It will become really popular or just disappear.
Another interesting thing about TechEd 2008 is what they didn’t talk about. Normally, these conferences are all using beta versions of something that hasn’t been released. I went to MEDC two years in a row and all they talked about was Whidbey (VS2005). Then it was all about Orcas (VS2008). With the exception of running VS2008 service pack 1 betas and a Silverlight beta, everyone was pretty content with the released software (quite a change from previous conferences). Does this mean there isn’t anything new in the queue or they are just taking a little longer to ramp up to the new stuff.

All and all, I was pretty pleased with the conference. Visual Studio 2008 looks good enough now to upgrade to (although I may wait until SP1 until I start upgrading all of my projects). Check out the full video and text of Bill Gates’ key: http://www.microsoft.com/presspass/exec/billg/speeches/2008/06-03teched.mspx

Getting Selection and Arrow keys to behave right with a ListBox in the.NET Compact Framework

2008-06-12T05:23:00.000-07:00

I had a form in a Window Mobile application that contains a Label and a ListBox. I wanted the ListBox to behave according to the Windows Mobile UI guidelines where you click on an item with the stylus and it is automatically selected. I used the SelectedIndexChanged event to implement this behavior and it worked fine when an item was selected with the stylus. However, with all of the different kinds of devices, many of them have partial or even full keyboards and at the very least they have a joypad or equivalent, my users were wanting to use the arrow keys to navigate to a specific item in the list and then press the enter button (never using the stylus). Unfortunately, the SelectedIndexChanged event is fired anytime the ListBox’s selected item is change (by stylus or keys) and since using the arrow keys usually requires scrolling through several items before getting to the item you want, the next item in the list is always selected (be it the one you want or not). I could not find a way in the .NET Compact Framework to get the ListBox to work like I wanted.

My solution was to replace the ListBox with a ListView. Change the View property to Details and change the Activation property to OneClick. Then use the ItemActivate event provided by the ListView instead of the SelectedIndexChanged event. You also have to add at least one Column to the ListView, and you can optionally set HeaderStyle to None to get rid of the column header and make the ListView look just like a ListBox.

Not xxx Is Nothing and xxx IsNot Nothing in VB.NET

2008-05-29T12:10:00.000-07:00

It took me a while to figure that that you can say:

If var1 IsNot Nothing Then
...
End If

Instead of the awkward:

If Not var1 is Nothing Then
...
End If

Of course the IsNot is like the Is and will work with when comparing any two object references, not just for testing for Nothing.

Finding the "My Documents" folder in VB.net

2008-05-20T15:01:00.000-07:00

Finding the My Documents folder in VB.NET (or C#) is pretty simple:

Dim dir as String
dir = System.Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)

There are several other special folders you can get as well:

Personal (My Documents also work on devices)
MyPictures
DesktopDirectory
MyMusic
StartMenu
Startup
Favorites
ApplicationData
CommandApplicationData
CommonProgramFiles
Cookies
History
InternetCache
LocalApplicationData
MyComputer
ProgramFiles
Programs
Recent

Here is another article on using SpecialFolders:

http://www.thescarms.com/dotnet/SpecialFolders.aspx

StartupPosition for MessageBox

2008-05-16T09:41:00.000-07:00

Sometimes it seems that .NET has some obvious shortcomings. For example, all I want to do is have a MessageBox center in my application instead of the screen. This task shouldn't be that difficult; however, there is no way (that I have found) to set the StartPosition property for the MessageBox dialog. While there may be a functional and elegant solution to this problem (please post as a comment if you have one), the only solution I have found on the internet is to implement your own MessageBox class, and code it to do what you want. This isn't hard, but it doesn't seem like a lot of work for something so simple. Also, the Messagebox probably does more than you might first think. It does a lot of autosizing to hold whatever text you provide it.

Here is one implementation of a custom MessageBox I have found:

http://www.codeproject.com/KB/dialog/MessageBoxEx.aspx?fid=155440&df=90&mpp=25&noise=3&sort=Position&view=Quick&fr=76&select=1069708

I am sure there are more such implementations. Please post comments if you know of any.

Finding VB.NET or C# Signatures for Interop/PInvoke

2008-05-14T13:38:00.000-07:00

There are several places to find the Signatures in VB.NET and C# for Win32Api calls online. Here is one that is pretty good:

http://pinvoke.net

Defaulting to Thumbnail View when using OpenFileDialog

2008-05-14T09:33:00.000-07:00

You would think that it would be very simple to default an OpenFileDialog to any view type you want via its properties. However, there is no property exposed for setting the view type. I simply want to browse for images with my OpenFileDialog instance, and I would prefer for the user not to have to manually set the view type to Thumbnail everytime.

I found a couple of solutions:

http://www.codeproject.com/cs/miscctrl/FileDialogExtender.asp (C#)

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=2741273&SiteID=1&mode=1 (same as above only in VB.NET)

and the following offers even more functionality:

http://www.codeproject.com/KB/dialog/OpenFileDialogEx.aspx

If someone else has found or created a better solution, please let me know.

Converting VB.NET to C# and C# to VB.NET

2008-05-12T15:55:00.000-07:00

Here is a web site that will quickly converting VB.NET to C# or C# to VB.NET:

http://labs.developerfusion.co.uk/convert/csharp-to-vb.aspx

It is not perfect, but it does all of the grunt work and it is free.