把MFC程序保存为图片 vc ++

void CCBilinearView::OnFileSave()
{
 CDC* pDC = GetWindowDC();  
    CBitmap bitmap;  
    CDC memDC ;  
    CRect rect;  
    GetClientRect(rect);  
    memDC.CreateCompatibleDC(pDC);  
 
    bitmap.CreateCompatibleBitmap(pDC,rect.Width(),rect.Height());  
    memDC.SelectObject(&bitmap);  
    memDC.BitBlt(0,0,rect.Width(),rect.Height(),pDC,0,0,SRCCOPY);  
 
    CFileDialog fDlg(FALSE,_T("bmp"),NULL,OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,_T("位图文件|*.bmp"),this);  
    if (fDlg.DoModal()==IDOK)  
    {  
  
        CString bmpfile = fDlg.GetPathName();  
  
        CFile file(bmpfile,CFile::modeCreate|CFile::modeWrite);  
  
        BITMAP bInfo;  
        bitmap.GetBitmap(&bInfo);  
  
        //计算调色板大小  
        int panelsize = 0;  
        if (bInfo.bmBitsPixel<24) //非真彩色  
        {  
            panelsize = pow((double)2,bInfo.bmBitsPixel)*sizeof(RGBQUAD);  
        }  
  
        //定义位图信息  
        BITMAPINFO*  bMapInfo = (BITMAPINFO*)LocalAlloc(LPTR,sizeof(BITMAPINFO)+panelsize);  
        bMapInfo->bmiHeader.biBitCount = bInfo.bmBitsPixel;  
        bMapInfo->bmiHeader.biClrImportant = 0;  
        bMapInfo->bmiHeader.biCompression = 0;  
        bMapInfo->bmiHeader.biHeight = bInfo.bmHeight;  
        bMapInfo->bmiHeader.biPlanes = bInfo.bmPlanes;  
        bMapInfo->bmiHeader.biSize = sizeof(BITMAPINFO);  
        bMapInfo->bmiHeader.biSizeImage = bInfo.bmHeight*bInfo.bmWidthBytes;  
        bMapInfo->bmiHeader.biWidth = bInfo.bmWidth;  
        bMapInfo->bmiHeader.biXPelsPerMeter = 0;  
        bMapInfo->bmiHeader.biYPelsPerMeter = 0;  
  
        //获取位图的实际数据  
        char* pData = new char[bMapInfo->bmiHeader.biSizeImage];  
        int len = GetDIBits(pDC->m_hDC,bitmap,0,bInfo.bmHeight,pData,bMapInfo,DIB_RGB_COLORS);  
  
        BITMAPFILEHEADER bFileHeader;  
        bFileHeader.bfType = 0x4D42;  
        bFileHeader.bfReserved1 = 0;  
        bFileHeader.bfReserved2 = 0;  
        bFileHeader.bfSize = sizeof(BITMAPFILEHEADER);   
        bFileHeader.bfOffBits = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)+panelsize;  
  
        //向文件中写入位图数据  
        file.Write(&bFileHeader,sizeof(BITMAPFILEHEADER));  
        file.Write(&bMapInfo->bmiHeader,sizeof(BITMAPINFOHEADER));  
        file.Write(pData,bMapInfo->bmiHeader.biSizeImage+panelsize);  
        file.Close();  
        delete pData;  
        LocalFree(bMapInfo);  
    }  
    bitmap.DeleteObject();  
    memDC.DeleteDC();
}