Subclassing (Spy++ alike)

[Guest]

Hi,

I need to write a functionality to catch all Windows Messages from any
Window (like spy++ does). I thought that would be possible by subclassing the
window.

So I wrote a class that inherts from NativeWindow, Assigned a Handle from
another window and overrode the WndProc method.

BUT, I never catch any message EXCEPT if I assign the handle of my own
application's window...

Has anyone done something like this before?

I'm stuck at the moment....

Regards Alexander

 

[Andrew Kirillov]

Hello

If you want to trap windows messages of another application you should look
at hooks.

Here you can find more information:
1)
http://msdn.microsoft.com/library/d...ace/Windowing/Hooks/AboutHooks.asp?frame=true
2) http://www.codeproject.com/csharp/GlobalSystemHook.asp
3) http://www.codeproject.com/system/hooksys.asp

 

[Guest]

So,

I have tried to do some basic steps in windows hooking and wrote the
following code. This works fine, at least for some seconds, then the
application freezes and the explorer process is killed =D, what am I doing
wrong?

The hook callback delegate:
public delegate int HookProc(int code, IntPtr wParam, IntPtr lParam);
setting up the hook:
HookProc p = new HookProc(this.CallbackFunction);
this.hook = SetWindowsHookEx(HookType.WH_CALLWNDPROC, p,
Marshal.GetHINSTANCE(typeof(Class1).Module),0);
Callback implementation:
private int CallbackFunction(int code, IntPtr wParam, IntPtr lParam)
{
if (code < 0)
{
return CallNextHookEx(this.hook, code, wParam, lParam);
}
int ret;
try
{
Message msg = (Message)Marshal.PtrToStructure(lParam, typeof(Message));
Console.WriteLine(msg);
}
catch
{
Console.WriteLine("exception");
}
finally
{
ret = CallNextHookEx(this.hook, code, wParam, lParam);
}
return ret;
}

Regards Alexander