/// <summary>
/// Paint the border
/// </summary>
/// <param name="m"></param>
private void WMNCPaint(ref Message m)
{
IntPtr hDC = NativeWindowCommon.GetWindowDC(m.HWnd);
if (hDC != IntPtr.Zero)
{
IntPtr hrgnWindow = IntPtr.Zero;
IntPtr hrgnClient = IntPtr.Zero;
try
{
Rectangle rect = new Rectangle(1, 1, Width - 2, Height - 2);
hrgnWindow = NativeWindowCommon.CreateRectRgn(0, 0, Width, Height);
hrgnClient = NativeWindowCommon.CreateRectRgn(rect.Left, rect.Top, rect.Right, rect.Bottom);
//Creates the union of two combined regions except for any overlapping areas.
NativeWindowCommon.CombineRgn(hrgnWindow, hrgnWindow, hrgnClient, NativeWindowCommon.RGN_XOR);
NativeWindowCommon.SelectClipRgn(hDC, hrgnWindow);
using (Graphics g = Graphics.FromHdc(hDC))
{
g.Clear(VisualStyleInformation.TextControlBorder);
}
m.Result = IntPtr.Zero;
}
finally
{
NativeWindowCommon.ReleaseDC(m.HWnd, hDC);
if (hrgnWindow != IntPtr.Zero)
{
NativeWindowCommon.DeleteObject(hrgnWindow);
}
if (hrgnClient != IntPtr.Zero)
{
NativeWindowCommon.DeleteObject(hrgnClient);
}
}
}
}