Capturing window image in windows server 2008
- by Sergey Osypchuk
I am capturing output of windows program using following function:
public static Bitmap Get(IntPtr hWnd, int X1, int Y1, int width, int height)
{
WINDOWINFO winInfo = new WINDOWINFO();
bool ret = GetWindowInfo(hWnd, ref winInfo);
if (!ret)
{
return null;
}
int curheight = height;
if (curheight <= 0 || curheight > winInfo.rcWindow.Height)
curheight = winInfo.rcWindow.Height;
int curwidth = width;
if (curwidth <= 0 || curwidth > winInfo.rcWindow.Width)
curwidth = winInfo.rcWindow.Width;
if (curheight == 0 || curwidth == 0) return null;
Graphics frmGraphics = Graphics.FromHwnd(hWnd);
IntPtr hDC = GetWindowDC(hWnd); //gets the entire window
//IntPtr hDC = frmGraphics.GetHdc(); -- gets the client area, no menu bars, etc..
System.Drawing.Bitmap tmpBitmap = new System.Drawing.Bitmap(curwidth, curheight, frmGraphics);
Graphics bmGraphics = Graphics.FromImage(tmpBitmap);
IntPtr bmHdc = bmGraphics.GetHdc();
BitBlt(bmHdc, 0, 0, curwidth, curheight, hDC, X1, Y1, TernaryRasterOperations.SRCCOPY);
bmGraphics.ReleaseHdc(bmHdc);
ReleaseDC(hWnd, hDC);
return tmpBitmap;
}
On Development environment everything is excellent, but on windows server 2008 I have following issues:
1) When there is other window in front my - it is getting captured as well
2) When there is no user connected to RDC - image is black
On other hand, I am able to render webpage images using IE. How I can change behaviour of windows rendering process to get proper results?
