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posts tagged with csharp

C# 3.0 looks like Smalltak

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By Fons Sonnemans, 14-sep-2005

Many years ago I programmed in Smalltalk (Enfin which later became ObjectStudio). I have always liked it although it was not very programmer friendly (no IntelliSense). I have just wachted this C# 3.0 Language Enhancements in action video. The shown Extension Methods feature realy looks like the Secondary Class files of Smalltalk. Nice to see them back, they where very handy.

In the following example I have added the 'IsPrime()' method to the 'Int32' type. The 'this' keyword in front of the 'number' parameter of the IsPrime() method did the real trick. This makes it an Extension Method.

class Program {
   &nbspstaticvoid Main(string[]args){
   &nbsp   &nbspConsole.WriteLine(5.IsPrime());// true
   &nbsp   &nbspConsole.WriteLine(9.IsPrime());// false
   &nbsp   &nbspConsole.WriteLine(23.IsPrime());// true
   &nbsp}
}

staticclass Extensions {

   &nbsppublicstaticbool IsPrime(thisintnumber){
   &nbsp   &nbspif(number==1||number==2||number==3){
   &nbsp   &nbsp   &nbspreturntrue;
   &nbsp   &nbsp}
   &nbsp   &nbspif((number%2)==0){
   &nbsp   &nbsp   &nbspreturnfalse;
   &nbsp   &nbsp}
   &nbsp   &nbspintsqrt=(int)Math.Sqrt(number);
   &nbsp   &nbspfor(int t =3; t <=sqrt; t = t +2){
   &nbsp   &nbsp   &nbspif(number% t ==0){
   &nbsp   &nbsp   &nbsp   &nbspreturnfalse;
   &nbsp   &nbsp   &nbsp}
   &nbsp   &nbsp}
   &nbsp   &nbspreturntrue;
   &nbsp}
}
Tags: CSharp

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My Favorite Visual Studio 2005 and .NET 2.0 features

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By Fons Sonnemans, 05-aug-2005
  • C# 2.0
  • Class Designer
  • Unit Testing
  • Code Coverage
  • FXCop Integration
  • Debugging: DataTips, Visualizers and Viewers
  • Refactoring
  • Improved IntelliSense
  • Code Snippets
  • Profiles
  • Strongly-typed resource class generator
  • Improved (not perfect) Windows Forms controls

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Binary Compatiblity

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By Fons Sonnemans, 22-jul-2005

Microsoft has released a free LibCheck tool that allows you to compare two versions of an assembly, and determine the differences. The tool reports the differences as a combination of 'removed' and 'added' APIs. The tool is limited to looking only at APIs (i.e, it can't check for behavioral changes), and only compares public differences, or changes which are deemed to be 'breaking'. The tool can be used to quickly determine what has changed between one version of your assembly and another, and can help ensure that you won't introduce any breaking changes to clients of your assembly. Instructions and intended use of the tool are described in the 'libcheck tool specification' document with the zip file.

This was a feature I always was missing. VB6 had this, VS.NET didn't. Thanks MS.

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Microsoft has put my 'Dual List' .NET Magazine article online!

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By Fons Sonnemans, 09-apr-2005

Microsoft has put my Visueel programmeren met .NET: Dual List Control article online. It is published in the .NET Magazine #8 and it is free for Dutch developers.
They didn't publish the sourcecode (yet) but you can download it from my own site. The aricle is in Dutch. You can find an (old) English version of this article here. An even more advanced implementation that also supports Drag & Drop can be found here.

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WaitCursor

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By Fons Sonnemans, 10-feb-2005

For a long time I thought that I only had to set the Cursor.Current to a WaitCursor before a long running operation, the .NET runtime would reset it back to the Default cursor. Turns out that this is only true when the mouse is moved. Bummer.

// Cursor.Current are automatically reset to Default when the
// mouse is moved and the application is idle!
Cursor.Current = Cursors.WaitCursor;

The solution for this problem is very easy. I created a helper class called WaitCursor which set the Cursor.Current and restores it to the original value when it it disposed.

public sealed class WaitCursor : IDisposable {   &nbsp   &nbsp   &nbsp   &nbsp
   &nbspprivate Cursor _prev;

   &nbsppublic WaitCursor(){
   &nbsp   &nbsp_prev= Cursor.Current;
   &nbsp   &nbspCursor.Current = Cursors.WaitCursor;
   &nbsp}

   &nbsppublicvoid Dispose(){
   &nbsp   &nbspCursor.Current =_prev;
   &nbsp}
}

I create the instance of the WairCursor class inside a using statement. This will automatically call the Dispose() method when it goes out of scope.

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Dispose Modal WinForm Dialogs

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By Fons Sonnemans, 12-dec-2004

There is a difference in disposing Modal and Non-Modal forms. In a training I gave last week I noticed that even experienced developers didn't know that Modal Dialogs don't dispose automatically, Non-Modal do.

private void buttonShowNonModalForm ( object sender , System.EventArgs e){
   &nbspnew TestForm().Show();
}

privatevoidbuttonShowModalDialog(objectsender, System.EventArgs e){
   &nbspnew Form2().ShowDialog();
}

The solution to this problem is very simple by creating the Form instance within a using block. This will dispose the Form when it is closed.

private void buttonShowModalDialog ( object sender , System.EventArgs e){
   &nbspusing(TestForm f =new TestForm()){
   &nbsp   &nbspf.ShowDialog();
   &nbsp}
}

An alternative solution uses a try/finnaly. Personally I prefer the previous, it is easier to read and write.

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C# HandleWhiteSpace Add-In

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By Fons Sonnemans, 23-sep-2004

Download WhiteSpace.zip

Introduction

The C# code editor in Visual Studio.NET 2003 does not handle whitespaces automatically like the VB.NET code editor does. This Add-In solves this problem by adding the 'Handle WhiteSpace' menu option to the Visual Studio.NET 2003 Tools menu. This option formats the C# code of the active code editor. This includes:

  • Space before:  method declaration parentheses, method call parentheses, statement parentheses, braces and brackets
  • Space after: comma and semicolon
  • Space around: operators
  • Double space

Example


Screen shot: Handle WhiteSpace menu option

After you have selected the menu option the C# source code is formatted with correct whitespaces.


Screen shot: Reformatted code

Conclusion

Writing clean C# code has become easier with this Add-In. I hope you enjoy using it.

I thank Heindirk de Laat for providing me the code for the most difficult part of the program. I only added some extra regular expressions and transformed it into an Add-In.

Any suggestions and feedback for improving this Add-In is most welcome. Send your suggestions and feedback to Fons.Sonnemans@reflectionit.nl


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ToolboxBitmap workaround

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By Fons Sonnemans, 03-sep-2004

I have found a solution for a problem which I had for a long time. I was unable to set the ToolboxBitmap attribute for a component using the (type, string) constructor. I found the solution for this problem (using an internal ResFinder class) on www.bobpowell.net. This site has also some other Windows Forms Tips and Tricks. Great!

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Visual C# 2005 Express Edition Beta is great

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By Fons Sonnemans, 14-jul-2004

I'm testing Visual C# 2005 Express Edition Beta and I really like it. It has all of the features which I need to build Windows Forms applications. The Editor has also all new IntelliSense, Refactoring and Code Snippets features. They work great and really can boost productivity.

I have tested it on a PC with only 256Mb of ram. This is for the beta not enough. You need at least 512Mb.

I'm using the Online MSDN Help, it works OK. The looks are good but I find it difficult to get to the 'overview' of a class.

For professional development I would advise to use Visual Studio. For hobby work use the Express versions.

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String Array Sorting

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By Fons Sonnemans, 27-apr-2004

It took me today some time to figure out how to sort an array of strings case-sensitively. The default behavior of the Array.Sort() uses an default Comparer object which should be case-sensitive. When I tested this I found out that I had misinterpreted the definition of 'case-sensitive'. What I wanted was 'Oridinal' sorting. So I created an OrdinalStringComparer class which implements IComparer and I got what I wanted.

using System;
using System.Collections;

namespace ReflectionIT.Test {

   &nbspclass Class1{

   &nbsp   &nbsp[STAThread]
   &nbsp   &nbspstaticvoid Main(string[]args){

   &nbsp   &nbsp   &nbspTest(new CaseInsensitiveComparer());
   &nbsp   &nbsp   &nbspTest(Comparer.Default);   &nbsp   &nbsp
   &nbsp   &nbsp   &nbspTest(new OridinalStringComparer());
   &nbsp   &nbsp
   &nbsp   &nbsp   &nbspConsole.ReadLine();
   &nbsp   &nbsp}

   &nbsp   &nbspprivatestaticvoid Test(IComparer comparer){

   &nbsp   &nbsp   &nbspstring[]words=newstring[]{"c","a","A","aB","ab","Ab"};

   &nbsp   &nbsp   &nbspArray.Sort(words,comparer);
   &nbsp   &nbsp
   &nbsp   &nbsp   &nbspConsole.WriteLine(comparer.GetType().Name +":");
   &nbsp   &nbsp   &nbspforeach(stringwordinwords){
   &nbsp   &nbsp   &nbsp   &nbspConsole.WriteLine(word);
   &nbsp   &nbsp   &nbsp}
   &nbsp   &nbsp   &nbspConsole.WriteLine();
   &nbsp   &nbsp}
   &nbsp   &nbsp
   &nbsp}
   &nbsp   &nbsp
   &nbsppublicclass OridinalStringComparer : IComparer {
   &nbsp   &nbsp
   &nbsp   &nbspint IComparer.Compare(object x,object y ){
   &nbsp   &nbsp   &nbspreturnstring.CompareOrdinal((string)x,(string)y);
   &nbsp   &nbsp}
   &nbsp   &nbsp
   &nbsp}
   &nbsp   &nbsp
}

And when you run this program you get the following output:

CaseInsensitiveComparer:
A
a
Ab
ab
aB
c

Comparer:
a
A
ab
aB
Ab
c

OridinalStringComparer:
A
Ab
a
aB
ab
c

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