Antwort
Also alle antworten sind ein FAIL :D
Hier: (in c#)
public const int GWLEXSTYLE = -20; public const int WSEXLAYERED = 0x80000; public const int LWAALPHA = 0x2; public const int LWA_COLORKEY = 0x1;
private void MakeTransparent(IntPtr Handle)
{
SetWindowLong(Handle, GWL_EXSTYLE, GetWindowLong(Handle, GWL_EXSTYLE) ^ WS_EX_LAYERED);
SetLayeredWindowAttributes(Handle, 0, 128, LWA_ALPHA);
}