WinForm Specifies a screenshot of the control area (such as intercepting a panel area in a form)

    <summary>///auxiliary class definition GDI32 API function///</summary> public class GDI32 {public Co        NST int srccopy = 0x00cc0020;                        [DllImport ("Gdi32.dll")] public static extern bool BitBlt (IntPtr hobject, int nxdest, int nydest, int nwidth,        int nheight, IntPtr hobjectsource, int nxsrc, int nysrc, int dwrop);        [DllImport ("Gdi32.dll")] public static extern IntPtr CreateCompatibleBitmap (IntPtr hDC, int nwidth, int nheight);        [DllImport ("Gdi32.dll")] public static extern IntPtr CreateCompatibleDC (IntPtr HDC);        [DllImport ("Gdi32.dll")] public static extern bool DeleteDC (IntPtr HDC);        [DllImport ("Gdi32.dll")] public static extern bool DeleteObject (IntPtr hobject);    [DllImport ("Gdi32.dll")] public static extern IntPtr SelectObject (IntPtr HDC, IntPtr hobject);   }///<summary>///auxiliary class definition User32 API function///</summary> public class User32 {     [StructLayout (layoutkind.sequential)] public struct RECT {public int left;            public int top;            public int right;        public int bottom;        } [DllImport ("User32.dll")] public static extern IntPtr GetDesktopWindow ();        [DllImport ("User32.dll")] public static extern IntPtr GETWINDOWDC (IntPtr hWnd);        [DllImport ("User32.dll")] public static extern IntPtr ReleaseDC (IntPtr hWnd, IntPtr HDC);    [DllImport ("User32.dll")] public static extern IntPtr GetWindowRect (IntPtr hWnd, ref rect rect); Call: (can be passed to control handle) public Image CaptureWindow (IntPtr handle) {IntPtr hdcsrc = USER32.GETWINDOWDC (han            DLE);            User32.rect windowrect = new User32.rect ();            User32.getwindowrect (handle, ref windowrect);            int width = Windowrect.right-windowrect.left;            int height = windowrect.bottom-windowrect.top; IntPtr hdcdest = GDI32. CreateCompatibledc (HDCSRC); IntPtr hbitmap = GDI32.            CreateCompatibleBitmap (hdcsrc, width, height); IntPtr hold = GDI32.            SelectObject (Hdcdest, HBITMAP); GDI32. BitBlt (hdcdest, 0, 0, width, height, hdcsrc, 0, 0, GDI32.            SRCCOPY); GDI32.            SelectObject (Hdcdest, hold); GDI32.            DeleteDC (hdcdest);            USER32.RELEASEDC (handle, HDCSRC);            Image img = image.fromhbitmap (HBITMAP); GDI32.            DeleteObject (HBITMAP);        return img; }

　　

WinForm Specifies the control area (for example, a panel area in the interception form)