screen capture..

I have two monitors, So I'd like to save it for ecah monitor.

So I get monitors' handle , and DC from EnumDisplayMonitor and MonitorEnumProc.

Code:

---

HMONITOR hMonitorHandle[2];
HDC  hdcMonitor[2];
CRect area[2];
CString filename[2] = {"firstMonitor.jpg", "secondMonitor.jpg" };
int index=0;
BOOL CALLBACK MonitorEnumProc(HMONITOR hMonitor,HDC hdcMonitor,LPRECT lprcMonitor,LPARAM dwData)
{

  TCHAR sInfo[256];
  MONITORINFOEX mi;

  mi.cbSize=sizeof(MONITORINFOEX);
  GetMonitorInfo(hMonitor,&mi);
 

  //save two monior's handle and dc.
 
  (*(LPRECT)area[iindex])=*lprcMonitor;
  hMonitorHandle[index]=hMonitor;
  hdcMonitor[index++]=hdcMonitor;
   
  return TRUE;

}


//fr saving, I call  CaptureScreen(...) function...
for ( int i = 0 ; i < 2 ;i++ )
{
    //first screen saved succesfully... but second screen is image  is black...
    //I don't know why second monitor not captured..   
    CaptureScreen( (HWND)hMonitorHandle[i], hdcMonitor[i],  area[i] , filename[i])
       

}


Void CaptureScreen( HWND hWnd, HDC hdc , Rect rect , CString filename)
{
    HWND hDesktopWnd = hWnd;
    //HDC hDesktopDC = GetDC(hDesktopWnd);
    HDC hDesktopDC = hdc ;

        CRect m_rDrawingSurface;
       
        BITMAPINFOHEADER BMIH;
        HBITMAP hCaptureBitmap;
        BYTE* m_pDrawingSurfaceBits;

        CDC* pDC = GetDC();
        if(pDC != NULL)
        {
                BMIH.biSize = sizeof(BITMAPINFOHEADER);
                BMIH.biBitCount = 24;
                BMIH.biPlanes = 1;
                BMIH.biCompression = BI_RGB;
                BMIH.biWidth = m_rDrawingSurface.Width();
                BMIH.biHeight = m_rDrawingSurface.Height();
                BMIH.biSizeImage = ((((BMIH.biWidth * BMIH.biBitCount) + 31) & ~31) >> 3) * BMIH.biHeight;
                hCaptureBitmap = CreateDIBSection(pDC->GetSafeHdc(), (CONST BITMAPINFO*)&BMIH, DIB_RGB_COLORS, (void**)&m_pDrawingSurfaceBits, NULL, 0);
                ReleaseDC(pDC);
        }

    //HBITMAP hCaptureBitmap =CreateCompatibleBitmap(hDesktopDC, nScreenWidth, nScreenHeight);
   
        SelectObject(hCaptureDC,hCaptureBitmap);
    BitBlt(hCaptureDC,
                0,
                0,
                m_rDrawingSurface.Width(),
                m_rDrawingSurface.Height(),
                hDesktopDC,0, 0,SRCCOPY|CAPTUREBLT);
 
  SaveitToBMP(hCaptureBitmap ,filename) //Place holder...


ReleaseDC(hDesktopWnd,hDesktopDC);
    DeleteDC(hCaptureDC);
    DeleteObject(hCaptureBitmap);

}

---

Is there a question somewhere in there?
Hard to see without the code tags.

I do not have second monitor attached to my system at the moment, so I can’t test this.
However, few things look odd in your code:

• you cast HMONITOR to HWND, which it isn’t
• you later assign it to local variable hDesktopWnd, which is not used in that function, except for in a call to ReleaseDC(hDesktopWnd,hDesktopDC); (but you never called GetDC() for it)
• your CDC* pDC = GetDC(); gets DC from the primary monitor, not for the one passed in; you already have HDC hdc parameter - why not use it?
• you are blitting to a hCaptureDC, but what is it?

If this is a pseudo code, there isn't much sense in looking for issues in it...