Easy way of Tracing open Data Reader

9. February 2012 11:32 by Mrojas in   //  Tags: , , , ,   //   Comments (0)

Finding DataReaders that are not being close in an .NET application can be something difficult.

Thats why I use this trick to detect which DataReaders where not close.

1. First add a new code file to your project.

2. Enter this code:

public static class SqlReaderTracer
		static Dictionary<WeakReference,System.Diagnostics.StackTrace> traceInfo = new Dictionary<WeakReference,System.Diagnostics.StackTrace>();
		public static System.Data.SqlClient.SqlDataReader ExecuteReaderEx(this System.Data.SqlClient.SqlCommand command)
			var stack = new System.Diagnostics.StackTrace(1, true);
			var reader = command.ExecuteReader();
			traceInfo.Add(new WeakReference(reader), stack);
			return reader;
		public static void PrintTraceState()
			Console.WriteLine("*******SQL Trace Results************");
			foreach (var reader in traceInfo.Keys)
				if (reader.IsAlive)
					var traceInfoFrame =  traceInfo[reader].GetFrame(0);
					var methodWhereItWasCreated =traceInfoFrame.GetMethod().DeclaringType.FullName + "." + traceInfoFrame.GetMethod();
					Console.Write("Reader alive created in " + methodWhereItWasCreated);
					if (traceInfoFrame.GetFileName() != null)
						Console.Write(string.Format("at {0} ({1},{2})",traceInfoFrame.GetFileName(),traceInfoFrame.GetFileLineNumber(),traceInfoFrame.GetFileColumnNumber()));


And then to a Find /Replace All and change all the .ExecuteReader() for .ExecuteReaderEx(). 3. Ok Now. You are all set. To test it do something like this:

class Program
		static void Main(string[] args)
			var xxx = new System.Data.SqlClient.SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=D:\MyProjects\Phonebook.mdf;Integrated Security=True");
			var ccc = xxx.CreateCommand();
			ccc.CommandText = "SELECT * from Phonebook";
			var reader = ccc.ExecuteReaderEx();

And you will see an output like:

Free Alternatives for .NET Reflector

6. October 2011 06:26 by Mrojas in   //  Tags: , ,   //   Comments (0)

As I use to start stories to my kids when they go to bed:

“A long long time ago when I was a kid there existed a tool called
.NET Reflector, by a great wizard called Lutz Roeder. This wizard created
a magical tool that allowed you to discover what where the dark forces of the
Framework that produced weird behavior. And he provided it to the code warrior so
they could find their path”

Well .NET Reflector still exists and is a great tool, but is no longer free. You can no longer
just download it and enjoy its bliss : S

But is everything loss. Should I sell my sword and horse to be able to use the .NET reflector Oracle jQuery15203662828153464943_1359277348820?

No. There are now good free alternatives.

First one is call ILSpy(http://wiki.sharpdevelop.net/ILSpy.ashx). It looks almost the same as .NET reflector. Is not the same but is very good

And recently JetBrains a clan of powerful code warlocks, has just release another magical jewel,
they called it dotPeek (http://www.jetbrains.com/decompiler/):

Fixing memory Leaks, Finalizer and other ugly problems in your .NET code

8. September 2011 07:48 by Mrojas in General  //  Tags: , , , ,   //   Comments (0)

Fixing memory leaks is sometimes hard. Because even if you track which is the instance
that is being retained, is difficult to determine WHERE was it created.

Another problem I have found difficult to tackle is when you get an exception because of
code that was put in a finalizer (yes I know that putting code in a Finalizer doesn’t sound like the
best programming practice but sometime I just have to give maintenance to code that does that).

So, my friend Jose de Jesus showed me a nice tip to identify where are those objects being created.

He told me to do the following:

1. Add an instance variable like:


public System.Diagnostics.StackTrace myClassStackTrace = new System.Diagnostics.StackTrace();

2. Just by doing that I can inspect that field and identify where was this particular instance created!.


Problems Debugging Silverlight with VS 2008

31. January 2011 10:58 by Mrojas in General  //  Tags: , ,   //   Comments (0)

If for any reason you have to debug and develop Silverlight VS 2008,
and you encounter a problem that when you start debugger it reports
something as if the version you have is not supported then first do this:

Open regedit and check:


A Version value of 4.0.50917.0 means that you have the Silverlight 4 Developer and you need to:

1. erase this entry.

2. Uninstall Silverlight 4 Tool

3. Reinstall Silverlight 3 Tools for Visual Studio 2008.

Internet Explorer Runtime Error Do you Wish to Debug?

4. February 2008 11:37 by Mrojas in General  //  Tags: ,   //   Comments (0)

Hi, for several months I lived with an extremely unconfortable bug.
On some pages IE will display an alert dialog indicating 

A Runtime Error has occurred.
Do you wish to Debug?
Line: blablabla
Error: blablalba

 Well finally I looked in google and found this: http://support.microsoft.com/kb/822521

So if anybody had to live with this bug like me, I hope this helps him

Here is a valuable comment I received. So I'm adding it so it will help somebody else.

I was plagued by the "Runtime error - do you wish to debug?" problem for months
and finally resolved it last night, after testing everything else in the MS knowledgebase
to no avail (http://support.microsoft.com/kb/308260/ln/).
The problem disappeared instantly after a tip-off elsewhere to install & run SpyBot. (Looks like my SpywareBlaster 4.1 failed me there.)
So it wasn't:
my IE 7 settings (Disable script debugging),
operating system (XP Pro SP3),
firewall (Comodo Pro),
antivirus (Avast!) or
scripting engine (WindowsScript 5.7) - just Spyware