public static extern IntPtr BeginPaint(IntPtr hWnd, ref PAINTSTRUCT ps);
public static extern bool EndPaint(IntPtr hWnd, ref PAINTSTRUCT ps);
protected override void WndProc(ref Message m)
{
if (m.Msg == 15)
{
if (!this._bPainting)
{
PAINTSTRUCT ps = new PAINTSTRUCT();
this._bPainting = true;
NativeMethods.BeginPaint(m.HWnd, ref ps);
this.DrawUpDownButton();
NativeMethods.EndPaint(m.HWnd, ref ps);
this._bPainting = false;
m.Result = Result.TRUE;
}
else
base.WndProc(ref m);
}
else
base.WndProc(ref m);
}