public static extern IntPtr GetWindowRect(IntPtr hwnd, ref NativeStructs.RECT rc);
public void Highlight()
{
NativeStructs.RECT windowRect = new NativeStructs.RECT(0, 0, 0, 0);
NativeMethods.GetWindowRect(handle, ref windowRect);
IntPtr windowDC = NativeMethods.GetWindowDC(handle);
if (windowDC != IntPtr.Zero)
{
Graphics graph = Graphics.FromHdc(windowDC, handle);
graph.DrawRectangle(highlightPen, 1, 1, windowRect.Width - 2, windowRect.Height - 2);
graph.Dispose();
NativeMethods.ReleaseDC(handle, windowDC);
}
}