jpeg to bmp 内存图像转换

不需要CxImage这样的第三方扩展库
微软的GDI+也可以转换的

C/C++ code

    
    
    
    

     
     
     
     CImage mmage; HWND hWnd 
     
     
     
     =
     
     
     
      ::GetDesktopWindow();
     
     
     
     //
     
     
     
     获得屏幕的HWND. 
     
     
     
      
     
     
     
      HDC hScreenDC 
     
     
     
     =
     
     
     
      ::GetDC(hWnd); 
     
     
     
     //
     
     
     
     获得屏幕的HDC. 
     
     
     
      
     
     
     
      HDC MemDC 
     
     
     
     =
     
     
     
      ::CreateCompatibleDC(hScreenDC); RECT rect; ::GetWindowRect(hWnd,
     
     
     
     &
     
     
     
     rect); HBITMAP hBitmap 
     
     
     
     =
     
     
     
      ::CreateCompatibleBitmap(hScreenDC,rect.right,rect.bottom); HGDIOBJ hOldBMP 
     
     
     
     =
     
     
     
      ::SelectObject(MemDC,hBitmap); ::BitBlt(MemDC,
     
     
     
     0
     
     
     
     ,
     
     
     
     0
     
     
     
     ,rect.right,rect.bottom,hScreenDC,rect.left,rect.top,SRCCOPY); hBitmap
     
     
     
     =
     
     
     
     (HBITMAP)::SelectObject(MemDC,hOldBMP); mmage.Attach(hBitmap); IStream
     
     
     
     *
     
     
     
      pStmImage 
     
     
     
     =
     
     
     
      NULL; HGLOBAL hMemBmp 
     
     
     
     =
     
     
     
      GlobalAlloc(GMEM_MOVEABLE,
     
     
     
     0
     
     
     
     );
     
     
     
     //
     
     
     
     可移动的缓冲区 
     
     
     
      
     
     
     
      
     
     
     
     if
     
     
     
      (hMemBmp 
     
     
     
     ==
     
     
     
      NULL) 
     
     
     
     return
     
     
     
      
     
     
     
     0
     
     
     
     ; CreateStreamOnHGlobal(hMemBmp, FALSE, 
     
     
     
     &
     
     
     
     pStmImage);
     
     
     
     //
     
     
     
     将内存区B作为流的起始 
     
     
     
      
     
     
     
      
     
     
     
     if
     
     
     
      (pStmImage 
     
     
     
     ==
     
     
     
      NULL) { GlobalFree(hMemBmp); AfxMessageBox(
     
     
     
     "
     
     
     
     为空
     
     
     
     "
     
     
     
     ); 
     
     
     
     return
     
     
     
      
     
     
     
     0
     
     
     
     ; } mmage.Save(pStmImage,Gdiplus::ImageFormatJPEG);