How to find source for win32 exception "error creating window handle"

Question

I'm looking for a little help regarding the win32 exception "error creating window handle". From time to time our program (WinForms - C#) throws this exception and sometimes the windows even freeze, so that the users have to kick the process to be able to work again.

From the many other threads regarding this problem, I know what I should be looking for, but not extactly where as our program is quite big. So I was hoping that there might be a way to restrict the codelines I have to check... Are the any tools, which can help with this exception?

Answer 1

Short update: I solved the problem.

ProcDump didn't help me much, because I got pretty the same information from our logfiles. However, I was able to reproduce the error in our development environment. Thanks to debugger and displaying the user-objects count in the taskmanager I found the source of the memoryleak - an undisposed texbox which was created dynamically.

Thanks again for the tips!

Answer 2

If this issue happens inside the debugger, you can set the debugger (I will assume Visual Studio as you're using C#?) to break on throwing an exception. In your case you would want to set an exception breakpoint on (I think) System.ComponentModel.Win32Exception.

Again assuming Visual Studio as your IDE, on the "Debug" menu is an "Exceptions..." item. This allows you to tell the debugger to break when specific exceptions are a) thrown, or b) unhandled.

Under Common Language Runtime Exceptions, expand System.ComponentModel, and enable the checkbox in the Thrown column for System.ComponentModel.Win32Exception.

Then just carry on as normal. If during debugging the exception occurs, it should break into your program and allow you to see where it's happening.

Edit: If you can't reproduce the problem on your development machines, see if you're able to set up the target machine to produce a dump when a crash occurs. One way of doing this is to run ProcDump. Run it with the -e parameter to create a dump in the event of an exception. Then you can analyse this back at the ranch.