private static void RegisterClassOnce()
{
if (!class_registered)
{
ExtendedWindowClass wc = new ExtendedWindowClass();
wc.Size = ExtendedWindowClass.SizeInBytes;
wc.Style = DefaultClassStyle;
wc.Instance = Instance;
wc.WndProc = WindowProcedure;
wc.ClassName = ClassName;
wc.Icon = IntPtr.Zero;
wc.IconSm = IntPtr.Zero;
wc.Cursor = LoadCursor(IntPtr.Zero, (IntPtr)CursorName.Arrow);
ushort atom = RegisterClassEx(ref wc);
if (atom == 0)
throw new Exception(String.Format("Failed to register window class. Error: {0}", Marshal.GetLastWin32Error()));
class_registered = true;
}
}
internal static extern ushort RegisterClassEx(ref ExtendedWindowClass window_class);