The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘C# 2.0’ Category

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.NET/C#/WinForms: small code snippet to enable Ctrl-A for select all in a single/multi-line TextBox

Posted by jpluimers on 2012/12/04

WinForms does not automatically enable Ctrl-A as “Select All” action.

The below code snippet works when you bind it to the KeyDown event of a TextBox (actually the event is on Control).

The e.SuppressKeyPress = true suppresses the bell sound in a multiline TextBox, as e.Handled = true won’t.

        private void textBox_KeyDown_HandleCtrlAToSelectAllText(object sender, KeyEventArgs e)
        {
            TextBox textBox = sender as TextBox;
            if (null != textBox)
            {
                if (e.Control && e.KeyCode == Keys.A)
                {
                    textBox.SelectAll();
                    e.SuppressKeyPress = true;
                }
            }
        }

–jeroen

Posted in .NET, .NET 1.x, .NET 2.0, .NET 3.0, .NET 3.5, .NET 4.0, .NET 4.5, C#, C# 1.0, C# 2.0, C# 3.0, C# 4.0, C# 5.0, Development, Software Development | Leave a Comment »

.NET/C# duh moment of the day: “A char can be implicitly converted to ushort, int, uint, long, ulong, float, double, or decimal (not the other way around; implicit != implicit)”

Posted by jpluimers on 2012/11/20

A while ago I had a “duh” moment while calling a method that had many overloads, and one of the overloads was using int, not the char I’d expect.

The result was that a default value for that char was used, and my parameter was interpreted as a (very small) buffer size. I only found out something went wrong when writing unit tests around my code.

The culprit is this C# char feature (other implicit type conversions nicely summarized by Muhammad Javed):

A char can be implicitly converted to ushort, int, uint, long, ulong, float, double, or decimal. However, there are no implicit conversions from other types to the char type.

Switching between various development environments, I totally forgot this is the case in languages based on C and Java ancestry. But not in VB and Delphi ancestry  (C/C++ do numeric promotions of char to int and Java widens 2-byte char to 4-byte int; Delphi and VB.net don’t).

I’m not the only one who was confused, so Eric Lippert wrote a nice blog post on it in 2009: Why does char convert implicitly to ushort but not vice versa? – Fabulous Adventures In Coding – Site Home – MSDN Blogs.

Basically, it is the C ancestry: a char is an integral type always known to contain an integer value representing a Unicode character. The opposite is not true: an integer type is not always representing a Unicode character.

Lesson learned: if you have a large number of overloads (either writing them or using them) watch for mixing char and int parameters.

Note that overload resolution can be diffucult enough (C# 3 had breaking changes and C# 4 had breaking changes too, and those are only for C#), so don’t make it more difficult than it should be (:

Below a few examples in C# and VB and their IL disassemblies to illustrate their differnces based on asterisk (*) and space ( ) that also show that not all implicits are created equal: Decimal is done at run-time, the rest at compile time.

Note that the order of the methods is alphabetic, but the calls are in order of the type and size of the numeric types (integral types, then floating point types, then decimal).

A few interesting observations:

  • The C# compiler implicitly converts char with all calls except for decimal, where an implicit conversion at run time is used:
    L_004c: call valuetype [mscorlib]System.Decimal [mscorlib]System.Decimal::op_Implicit(char)
    L_0051: call void CharIntCompatibilityCSharp.Program::writeLineDecimal(valuetype [mscorlib]System.Decimal)
  • Same for implicit conversion of byte to the other types, though here the C# and VB.NET compilers generate slightly different code for run-time conversion.
    C# uses an implicit conversion:
    L_00af: ldloc.1
    L_00b0: call valuetype [mscorlib]System.Decimal [mscorlib]System.Decimal::op_Implicit(uint8)
    L_00b5: call void CharIntCompatibilityCSharp.Program::writeLineDecimal(valuetype [mscorlib]System.Decimal)
    VB.NET calls a constructor:
    L_006e: ldloc.1
    L_006f: newobj instance void [mscorlib]System.Decimal::.ctor(int32)
    L_0075: call void CharIntCompatibilityVB.Program::writeLineDecimal(valuetype [mscorlib]System.Decimal)

Here is the example code: Read the rest of this entry »

Posted in .NET, Agile, Algorithms, C#, C# 1.0, C# 2.0, C# 3.0, C# 4.0, C# 5.0, C++, Delphi, Development, Encoding, Floating point handling, Java, Software Development, Unicode, Unit Testing, VB.NET | 1 Comment »

Some notes on finding the cause of a .NET app generating a “application has generated an exception that could not be handled”

Posted by jpluimers on 2012/11/15

A while ago, one of the users at a client got an error in a .NET 1.1 app of which the sources were not readily available:

“application has generated an exception that could not be handled”

I think it is a e0434f4d  exception.

This particular site has very strict rules about what you can and cannot do as a developer. Which means that on a production system, you basically cannot do anything.

A few links that should help me finding the solution, and escalate far enough upstream to get someone with local admin rights to assist me:

If WinDbg is allows to be ran, these should help me:

–jeroen

Posted in .NET, .NET 1.x, .NET 2.0, .NET 3.0, .NET 3.5, .NET 4.0, .NET 4.5, C#, C# 1.0, C# 2.0, C# 3.0, C# 4.0, C# 5.0, Development, Software Development | Leave a Comment »

Interesting: Visual Studio Project Renamer | ComVisible

Posted by jpluimers on 2012/11/14

Over the course of development time, each suite of projects is bound to get some renames.

Doing that from the Visual Studio IDE is a pain, so I was glad to find Visual Studio Project Renamer by ComVisible.

Though it only supports C# and VB.NET projects (so no solution rename or rename of F#, Database or Reporting Service projects, nor stuff outside of the Microsoft realm like Prism).

These Just geeks: Renaming a Visual Studio Project link led me to the project.

Renaming solutions still is largely a manual operation as it involves renaming directories. You have to re-add some (sometimes all) projects later where this tool can come in handy: CoolCommands by SharpToolbox.

–jeroen

via:

Posted in .NET, C#, C# 2.0, C# 3.0, C# 4.0, C# 5.0, Development, F#, Prism, Software Development, VB.NET, Visual Studio and tools | Leave a Comment »

.NET/C#: Drives, Directories, Paths and Filenames in Windows is hard, let alone cross platform (: via: .net – Why Path.Combine doesn’t add the Path.DirectorySeparatorChar after the drive designator? – Stack Overflow)

Posted by jpluimers on 2012/11/08

Handling names of drives and paths (directories, filenames) is hard in Windows, as both C:myfile.ext and C:\myfile.ext are valid – but potentially different – filenames, C is a valid driveletter, C: and C:\ are valid – but also potentially different – directory names.

This leads into confusion as how Path.Combine behaves.

Part of the confusion comes from the meaning of the absence or presence of the leading DirectorySeparatorChar as explained by user Peter van der Heijden:

C:filename is a valid path and is different from C:\filename. C:filename is the file filename in the current directory on the C: drive whereas C:\filename is the file filename in the root of that drive. Apparently they wanted to keep the functionality of refering to the current directory on some drive.

This behaviour is described here in MSDN

Another oddity is that Path.Combine will only use the drive portion of the left argument when the right argument contains an absolute path.

If you understand the above, then dealing with cross platform directory and path separators, spaces in filenames and UNC path names are peanuts (:

–jeroen

via: .net – Why Path.Combine doesn’t add the Path.DirectorySeparatorChar after the drive designator? – Stack Overflow.

Posted in .NET, C#, C# 2.0, C# 3.0, C# 4.0, C# 5.0, Development, Software Development | Leave a Comment »

C# Code fragments of the week

Posted by jpluimers on 2012/11/06

Boy, was I astonished to see the code fragments below in production apps. It is far more Daily WTF than Coding Horror.

However, it did make debugging the production problem at hand a lot worse than it should be.

First a few short pieces:

        private void method(Word.Application objNewDoc, string stringWithCsvSeparatedDotFileNames)
        {
            char c = char.Parse(",");
            string[] wordAddIns = stringWithCsvSeparatedDotFileNames.ToString().Split(c);
        }

It took me almost a minute to understand what happened here. Especially because the names of parameters actually were pretty meaningless.

                foreach (string sFilename in attachments)
                {
                    Word.Application mailDocument = new Word.Application();

                    string[] filePath = sFilename.Split('\\');

                    string tempDirectory = GetTempDirectoryFromConfigFile();
                    object fileName = tempDirectory + filePath[filePath.Length - 1];

                    File.Copy(sFile, (string)fileName, true);
                    // some code that actually does something with the attachment
                }

It took me more than a few minutes to realize that:

  1. The tempDirectory needs to end with a backslash
  2. mailDocument (not a document, see below), will stay alive when File.Copy(…) throws an exception.
        internal virtual bool Method(/* parameters */, Word.Application objDoc)
        {
            // lots of pre-initialized empty string variables that are used at the very end of the method

            Word.Application objNewDoc;
            if (objDoc != null)
            {
                objNewDoc = objDoc;
            }
            else
            {
                objNewDoc = new Word.Application();
            }

            // lots of Object variables for COM, including:
            Object missing = Missing.Value;
            Object bFalse = false;

            try
            {
                // lots of code that does not use objNewDoc
            }
            catch (IOException IOex)
            {
                objNewDoc.Quit(ref bFalse, ref missing, ref missing);
                objNewDoc = null;
                throw IOex;
            }
            catch (Exception ex)
            {
                objNewDoc.Quit(ref bFalse, ref missing, ref missing);
                objNewDoc = null;
                throw new Exception("Some error message.", ex);
            }
            finally
            {
                // empty finally block
            }

            try
            {
                // actual coder that does use objNewDoc
            }
            catch (Exception ex)
            {
                objNewDoc.Quit(ref bFalse, ref missing, ref missing);
                objNewDoc = null;
                throw new Exception("Some error message.", ex);
            }
            return true;
        }

I rewrote the whole piece into separate methods.

Luckily the person who wrote this got promoted away from programming a few years ago.

–jeroen

Posted in .NET, C#, C# 1.0, C# 2.0, C# 3.0, C# 4.0, C# 5.0, Development, Software Development | Leave a Comment »

.net – WinForms Load vs. Shown events – Stack Overflow

Posted by jpluimers on 2012/10/31

The order of events and what you can do in events is very important in Windows applications.

This includes the WinForms applications – still popular for business applications – the first .NET framework that supported building Windows applications.

WinForms has two important event/method combo’s:

In descendants, you override the methods. In the form designer, you use the events.

Both the methods and events rely on Windows messages to get fired. This means they depends on which message loop is active. And this limits in what you can do during them.

One of the things you should not do in Load or Show is perform a MessageBox, ShowDialog or any other form of message pumping (like in COM).

Hans Passant explains it this way:

Avoid using MessageBox.Show() to debug this [ed: debug Shown/Load behaviour]. It pumps a message loop, disturbing the normal flow of events. The Load event is triggered by Windows sending the WM_SHOWWINDOW message, just before the window becomes visible. There is no Windows notification for “your window is now fully shown”, so the WF designers came up with a trick to generate the Shown event. They use Control.BeginInvoke(), ensuring the OnShown() method gets called as soon as the program goes idle again and re-enters the message loop.

This trick has lots of other uses, particularly when you have to delay the execution of code started by an event. However, in your case it falls apart because you use MessageBox.Show(). Its message loop dispatches the delegate registered with BeginInvoke(), causing the Shown event to run before the window is shown.

Krishnan Sriram explains that if you use proper debug logging (see what Hans wrote), you get this order of events:

  1. Form – Client Size Changed : 8/14/2010 10:40:28 AM
  2. Form – Control Added – button1 : 8/14/2010 10:40:29 AM
  3. Form – Constructor : 8/14/2010 10:40:29 AM
  4. Form – Handle Created : 8/14/2010 10:40:29 AM
  5. Form – Invalidated : 8/14/2010 10:40:29 AM
  6. Form – Form Load event : 8/14/2010 10:40:29 AM
  7. Form – Loaded : 8/14/2010 10:40:29 AM
  8. Form – Create Control : 8/14/2010 10:40:29 AM
  9. Form – OnActivated : 8/14/2010 10:40:29 AM
  10. Form – Shown : 8/14/2010 10:40:29 AM
  11. Form – OnPaint : 8/14/2010 10:40:29 AM
  12. Form – Invalidated : 8/14/2010 10:40:29 AM
  13. Form – OnPaint : 8/14/2010 10:40:29 AM

Finally, Ahmed Said indicates that there can be form size differences in the Load and Shown state:

The Shown event occured after the load event, the main difference is not in the visibility but in state of the form (width,hieght,..etc). I will give you an example to clarify if we create a form with default size 100,200 and set the windowstate = Maximized in the load event the size will be 100,200 but in shown event the size will be your screen size

–jeroen

via: .net – WinForms Load vs. Shown events – Stack Overflow.

Posted in .NET, C#, C# 1.0, C# 2.0, C# 3.0, C# 4.0, C# 5.0, Development, Software Development, WinForms | Leave a Comment »

One or more types required to compile a dynamic expression cannot be found. Are you missing references to Microsoft.CSharp.dll and System.Core.dll (via: C# 4.0 and .Net 3.5 – Stack Overflow)

Posted by jpluimers on 2012/10/25

If you get any of the two errors below while compiling your .NET app, then one of these things happened:

  1. You moved .NET 4 or higher code that makes use of dynamic into an assembly that does not reference the Microsoft.CSharp.dll and System.Core.dll assemblies.
  2. You tried changing the .NET version of a project back to .NET 3.5 or lower.

Note that it is not so much declaring a variable as dynamic, but using that variable.

Predefined type ‘Microsoft.CSharp.RuntimeBinder.Binder’ is not defined or imported

One or more types required to compile a dynamic expression cannot be found. Are you missing references to Microsoft.CSharp.dll and System.Core.dll?

–jeroen

via C# 4.0 and .Net 3.5 – Stack Overflow.

Posted in .NET, .NET 4.5, C#, C# 2.0, C# 3.0, C# 4.0, C# 5.0, Development, Software Development | Leave a Comment »

Please fellow programmers, name variables more properly.

Posted by jpluimers on 2012/09/25

The code I had a hard time understanding

The below code didn’t compile during a .NET 1.1 to 4 migration.

Downstream code:

Word.Document document = app.Documents.Add(ref FileName, ref missing, ref missing, ref missing);

Upstream code (6 layers up!):

string filename = Path.Combine(ConfigurationSettings.AppSettings["MSWordTemplateDirectory"], (string)status["CoverLetter"]);

And somewhere in the middle:

public bool GenerateLetter(Word.Application app, DataRow row, object FileName, object FilePathAndName)

Afterwards the code is this

Downstream code:

Word.Document document = app.Documents.Add(ref templateFileName, ref missing);

Upstream code (6 layers up!):

templateFileName = Path.Combine(ConfigurationSettings.AppSettings["MSWordTemplateDirectory"], (string)status["CoverLetter"]);

And somewhere in the middle:

public bool GenerateLetter(Word.Application app, DataRow row, object templateFileName, object documentFileName)

Coincidentally, parameters are now all lowercase.

–jeroen

Posted in .NET, C#, C# 1.0, C# 2.0, C# 3.0, C# 4.0, C# 5.0, Development, Software Development | Leave a Comment »

Creating a blank Visual Studio solution without a directory, and sln Format Version numbers

Posted by jpluimers on 2012/09/06

A while ago, I blew quite a few Visual Studio Solution and Project builds because I was experimenting in a suite of solutions with the Configuration Manager adding other Solution Configurations than Release and Debug, and mixing x86/AnyCPU platforms to facilitate Debug & Continue.

Lesson learned: don’t do that!

Keep it simple:

  1. Keep your Solution Configurations at Release and Debug,
  2. Perform conditional defines in your automated build server,
  3. Limit the mixing your platforms to a minimum.

We noted the anomalies a little late in the process (in retrospect, when taking over the solution suite, we should have started with setting up and Build Automation right at the beginning, then fix all the solutions that came from Visual Source Shredder, but alas: you are never too old to learn from your mistakes).

The anomalies were spurious (and hard to reproduce) build failures at developer workstations, wrong builds of assemblies ending up on the final build directories and more. And best of all: Visual Studio not failing, warning or hinting upon most issues.

Fixing projects and solutions from wrong Solution Configurations

The history in the version control system was not helpful enough to assist in fixing it, so the fix was this:

  1. Manually edit the .csproj files, and remove the PropertyGroup elements other than “Debug|AnyCPU” and “Release”AnyCPU”.
    This is easy to do inside Visual Studio and with automatic checkout from TFS of the project files:

    1. In the Solution Explorer, select all the projects
    2. Right click on a project
    3. Choose “Unload Project”
      (because you selected all the projects, it is the second menu item from the bottom, and way easier to find when you do this per project)
    4. For each project
      1. Right click the project
      2. Choose “Edit ….”
      3. Remove the PropertyGroup elemts you don’t need
      4. Save and close the file
      5. Right click the project
      6. Choose “Reload Project”
  2. Fix the solution files

The last step is a lot more complex, because of a couple of reasons:

My workaround was as follows:

  1. Start with an empty solution in the same directory as the original solution
  2. Add all the Solution Folders, Solution Items, and projects to it that  were in the original solution
    (having two copies of Visual Studio next to each other on a dual monitor setup is of great help)
  3. Compare the .sln files to each other
  4. Check out the original .sln file
  5. Merge any changes into the original .sln file
  6. Build it
  7. Check in
  8. Run a build on the CruiseControl.net automated build server
  9. Fix build errors
  10. Delete the temporary local .sln file

Creating an empty solution in a directory

Finally, I get to the title of this blog entry: Visual Studio will always generate a directory when creating a Blank Solution, and does not support creating an Empty Solution in a directory.

There are many posts describing how to workaround this, but the actual downloads are usually gone because of link rot (Jakob Nielsen’s alert from 1998 still is totally right about it). Thanks to they webarchive.org WayBackMachine though for keeping some of them alive.

So I went with Peter Provost’s solution, and amended it from Visual Studio 2005 to all Visual Studio versions that support .NET that I have used or still use: 2002, 2003, 2005, 2008, 2010 and 2012 a.k.a. VS11.

All files are in Change set 89386 on BeSharp.CodePlex.com.

His solution uses the ShellNew command for .sln file extensions that is stored in the registry:

  1. Create an empty solution file for the Visual Studio version you are using
  2. Copy that as a template file to %Windir%\ShellNew
    (you need to be administrator for that)
  3. Import a small .reg file binding that template file to the ShellNew command for .sln files

ShellNew is versatile, so you can also embed the fresh solution file into the .reg file, see this ShellNew article for a few nice examples.

Note that generating a new ShellNew verb for .sln is something other than loading a .sln (loading a .sln is done through VisualStudioLauncher).

Back to the .sln file: this one is different for any version of Visual Studio. Historically, the basic format is the same though (and I think this – in combination with VisualStudioLauncher – is the main reason it is not XML).

An empty solution file looks like this (note the empty line at the beginning), as described in Hack the Project and Solution Files:


Microsoft Visual Studio Solution File, Format Version 12.00
# Visual Studio 11
Global
	GlobalSection(SolutionProperties) = preSolution
		HideSolutionNode = FALSE
	EndGlobalSection
EndGlobal

The accompanying .reg file like this:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\.sln\ShellNew]
"FileName"="Visual Studio Solution - VS11.sln"

When you look at the Format Version inside the .sln version, you see that it (12) is one bigger than the internal Visual Studio Version (11).

That is because Microsoft stepped up the internal version from Visual Studio .NET (2002) and Visual Studio 2003 from 7.0 to 7.1, but the solution file format version from 7.00 to 8.00 as the table below shows.

Note that the .NET 1.x versions of Visual Studio (2002 for .NET 1.0, 2003 for .NET 1.1) don’t have the GlobalSection/HideSolutionNode/EndGlobalSection part and the # Visual Studio xx line.

With a little bit of querying, I got at this table:

Visual Studio version Internal version Solution file format version
Visual Studio .NET (2002) 7.0 Microsoft Visual Studio Solution File, Format Version 7.00
Visual Studio 2003 7.1 Microsoft Visual Studio Solution File, Format Version 8.00
Visual Studio 2005 8.0 Microsoft Visual Studio Solution File, Format Version 9.00
Visual Studio 2008 9.0 Microsoft Visual Studio Solution File, Format Version 10.00
Visual Studio 2010 10.0 Microsoft Visual Studio Solution File, Format Version 11.00
Visual Studio 2012 (a.k.a. VS11) 11.0 Microsoft Visual Studio Solution File, Format Version 12.00

All files to get you going are in Change set 89386 on BeSharp.CodePlex.com.

It was a bit hard to get all those version numbers, so here are the sources I used:

–jeroen

Posted in .NET, C#, C# 1.0, C# 2.0, C# 3.0, C# 4.0, C# 5.0, Development, Internet, link rot, Power User, Software Development, Visual Studio 11, Visual Studio 2002, Visual Studio 2003, Visual Studio 2005, Visual Studio 2008, Visual Studio 2010, Visual Studio and tools, WWW - the World Wide Web of information | Leave a Comment »

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