screen capture..

[somez72]

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.

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);

}

[VladimirF]

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

[VladimirF]

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...