ScreenCapture with tool tips?

Wing

Member
Joined
May 13, 2007
Messages
15
Location
Sweden
Hi i use this class to take a screen capture but i want to include small yellow tooltips in my screen shot how do i do that?, if you press print screen then you get em in the picture so there should be a way?

Code:
    public class ScreenCapture
    {
        /// <summary>
        /// Creates an Image object containing a screen shot of the entire desktop
        /// </summary>
        /// <returns></returns>
        public Image CaptureScreen()
        {
            return CaptureWindow(User32.GetDesktopWindow());
        }

        /// <summary>
        /// Creates an Image object containing a screen shot of a specific window
        /// </summary>
        /// <param name="handle">The handle to the window. (In windows forms, this is obtained by the Handle property)</param>
        /// <returns></returns>
        private Image CaptureWindow(IntPtr handle)
        {
            // get te hDC of the target window
            IntPtr hdcSrc = User32.GetWindowDC(handle);
            // get the size
            User32.RECT windowRect = new User32.RECT();
            User32.GetWindowRect(handle, ref windowRect);
            int width = windowRect.right - windowRect.left;
            int height = windowRect.bottom - windowRect.top;
            // create a device context we can copy to
            IntPtr hdcDest = GDI32.CreateCompatibleDC(hdcSrc);
            // create a bitmap we can copy it to,
            // using GetDeviceCaps to get the width/height
            IntPtr hBitmap = GDI32.CreateCompatibleBitmap(hdcSrc, width, height);
            // select the bitmap object
            IntPtr hOld = GDI32.SelectObject(hdcDest, hBitmap);
            // bitblt over
            GDI32.BitBlt(hdcDest, 0, 0, width, height, hdcSrc, 0, 0, GDI32.SRCCOPY);
            // restore selection
            GDI32.SelectObject(hdcDest, hOld);
            // clean up 
            GDI32.DeleteDC(hdcDest);
            User32.ReleaseDC(handle, hdcSrc);
            // get a .NET image object for it
            Image img = Image.FromHbitmap(hBitmap);
            // free up the Bitmap object
            GDI32.DeleteObject(hBitmap);
            return img;
        }

        /// <summary>
        /// Helper class containing Gdi32 API functions
        /// </summary>
        private class GDI32
        {

            public const int SRCCOPY = 0x00CC0020; // BitBlt dwRop parameter
            [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>
        /// Helper class containing User32 API functions
        /// </summary>
        private 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);
        }
    }
 
Last edited by a moderator:
Have you tried using the Graphics.CopyFromScreen method? (Assuming you are using DotNet 2.0).
 
Well sure i could do that but that didnt slove the problem i still get no tool tips in the image it results...
 
Hmm... Im guessing the problem from all the methods that dont work, is that theyre operating off the window handle and having the window draw itself into the offscreen surface. Maybe the trick is to use the screens handle itself so that it can pick up all the windows, including the tooltip. Im sorry Ive got no code or link to help, but thought the info might spark something else to try if youve run dry.

-ners
 
Iv found a way to fix the problem :P
iv changed
GDI32.BitBlt(hdcDest, 0, 0, width, height, hdcSrc, 0, 0, GDI32.SRCCOPY);
to:
GDI32.BitBlt(hdcDest, 0, 0, width, height, hdcSrc, 0, 0, GDI32.SRCCOPY | GDI32.CAPTUREBLT);
and added public const int CAPTUREBLT = 1073741824; to the GDI32 class
 

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