FindWindow from user32.dll

[guiding5]

I am a newbie with C#

As i trying to find handle to window, i imported an external function from user32.dll :

[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern IntPtr FindWindow(string strClassName, string strWindowName);

It works fine when i send to function both arguments and retreives me a handle, but if i send only a ClassName i dont get a handle !!!

ClassName is enought for FindWindow() to return handle.

It doesnt works when i try :

IntPtr hWnd = FindWindow("MyClass", string.Empty);
IntPtr hWnd = FindWindow("MyClass", "");

If anybody knows how to solve this problem please help
If anybody knows how to get handle of any window in another way i will be greatefull to hear how

 

[chiph]

Try creating another FindWindow imported function header. This new one would take a 32-bit integer for the second argument, and you'd call it with a 0 value to pass in a c-style NULL (0x00000000).

What's happening with calling the first style FindWindow is even String.Empty ends up passing a valid (albeit empty) memory address to FindWindow, and it thinks you're looking for a window with no title.

Chip H.

 

[guiding5]

Thanks i`ll try ...
You mean like :

[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern IntPtr FindWindow(string strClassName, int nptWindowName);

??

 

[chiph]

Yes, like that. Let me know how well it works.

Chip H.

 

[guiding5]

This does works, i used IntPtr for second argument
and called function with IntPtr.Zero

Thanks !!!