public static extern IntPtr GetClientRect(IntPtr hWnd, ref NativeStructs.RECT rect);
/// <summary>
/// Requests the specified window to draw itself to a Bitmap
/// </summary>
/// <param name="handle">The handle of the window to draw</param>
/// <param name="clientArea">If the client area should be drawn or the whole window.</param>
/// <remarks>This method only works on windows that handle WM_PRINT. It allows for capturing non-visible and minimized applications.</remarks>
/// <returns>An image with the window drawn onto it.</returns>
public static Bitmap Print(IntPtr hWnd, bool clientArea)
{
NativeStructs.RECT r = new NativeStructs.RECT();
NativeMethods.GetWindowRect(hWnd, ref r);
Rectangle rect = r;
Bitmap bmp = new Bitmap(rect.Width, rect.Height);
using (Graphics g = Graphics.FromImage(bmp))
{
IntPtr hdc = g.GetHdc();
NativeMethods.PrintWindow(hWnd, hdc, 0);
g.ReleaseHdc(hdc);
}
if (clientArea)
{
NativeMethods.GetClientRect(hWnd, ref r);
Point pt = Point.Empty.ClientToScreen(hWnd);
Rectangle client = new Rectangle(pt, ((Rectangle)r).Size);
Bitmap crop = new Bitmap(client.Width, client.Height);
using (Graphics g = Graphics.FromImage(crop))
{
int titleHeight = client.Top - rect.Top;
g.DrawImage(bmp, new Point((client.Width - rect.Width) / 2, -titleHeight));
}
bmp.Dispose();
bmp = crop;
}
return bmp;
}
public static extern IntPtr GetWindowRect(IntPtr hWnd, ref NativeStructs.RECT rect);