保存屏幕BMP

[cpp]
HBITMAP CopyScreenToBitmap(LPRECT lpRect)
{
     //屏幕和内存设备描述表
     HDC hSrcDC, hMemDC;
     //位图句柄
     HBITMAP hBitmap, hOldBitmap;
     //选定区域坐标
     int nX, nY, nX2, nY2;
     //位图宽度和高度
     int nWidth, nHeight;
     //屏幕分辨率
     int xScrn, yScrn;

     //确保选定区域不为空矩形
     if(IsRectEmpty(lpRect))
      return NULL;
     //为屏幕创建设备描述表
     hSrcDC = CreateDC("DISPLAY", NULL, NULL, NULL);
     //为屏幕设备描述表创建兼容的内存设备描述表
     hMemDC = CreateCompatibleDC(hSrcDC);
     //获得选定区域坐标
     nX = lpRect->left;
     nY = lpRect->top;
     nX2 = lpRect->right;
     nY2 = lpRect->bottom;
     //获得屏幕分辨率
     xScrn = GetDeviceCaps(hSrcDC, HORZRES);
     yScrn = GetDeviceCaps(hSrcDC, VERTRES);
     //确保选定区域是可见的
     if(nX<0)
        nX = 0;
     if(nY<0)
        nY = 0;
     if(nX2>xScrn)
        nX2 = xScrn;
     if(nY2>yScrn)
        nY2 = yScrn;
     nWidth = nX2 - nX;
     nHeight = nY2 - nY;
     //创建一个与屏幕设备描述表兼容的位图
     hBitmap = CreateCompatibleBitmap(hSrcDC, nWidth, nHeight);
     //把新位图选到内存设备描述表中
     hOldBitmap = (HBITMAP)SelectObject(hMemDC, hBitmap);
     //把屏幕设备描述表拷贝到内存设备描述表中
     BitBlt(hMemDC, 0, 0, nWidth, nHeight, hSrcDC, nX, nY, SRCCOPY);
     //得到屏幕位图的句柄
     hBitmap = (HBITMAP)SelectObject(hMemDC, hOldBitmap);
     //清除
     DeleteDC(hSrcDC);
     DeleteDC(hMemDC);
     //返回位置句柄
     return hBitmap;
}
HBITMAP CopyScreenToBitmap(int x1, int x2, int y1, int y2)
{
     //屏幕和内存设备描述表
     HDC hSrcDC, hMemDC;
     //位图句柄
     HBITMAP hBitmap, hOldBitmap;
     //选定区域坐标
     int nX, nY, nX2, nY2;
     //位图宽度和高度
     int nWidth, nHeight;
     //屏幕分辨率
     int xScrn, yScrn;
     /*
     //确保选定区域不为空矩形
     if(IsRectEmpty(lpRect))
     return NULL;*/
     //为屏幕创建设备描述表
     hSrcDC = CreateDC("DISPLAY", NULL, NULL, NULL);
     //为屏幕设备描述表创建兼容的内存设备描述表
     hMemDC = CreateCompatibleDC(hSrcDC);
     //获得选定区域坐标
     nX = x1;
     nY = y1;
     nX2 = x2;
     nY2 = y2;
     //获得屏幕分辨率
     xScrn = GetDeviceCaps(hSrcDC, HORZRES);
     yScrn = GetDeviceCaps(hSrcDC, VERTRES);
     //确保选定区域是可见的
     if(nX<0)
        nX = 0;
     if(nY<0)
        nY = 0;
     if(nX2>xScrn)
        nX2 = xScrn;
     if(nY2>yScrn)
        nY2 = yScrn;
     nWidth = nX2 - nX;
     nHeight = nY2 - nY;
     //创建一个与屏幕设备描述表兼容的位图
     hBitmap = CreateCompatibleBitmap(hSrcDC, nWidth, nHeight);
     //把新位图选到内存设备描述表中
     hOldBitmap = (HBITMAP)SelectObject(hMemDC, hBitmap);
     //把屏幕设备描述表拷贝到内存设备描述表中
     BitBlt(hMemDC, 0, 0, nWidth, nHeight, hSrcDC, nX, nY, SRCCOPY);
     //得到屏幕位图的句柄
     hBitmap = (HBITMAP)SelectObject(hMemDC, hOldBitmap);
     //清除
     DeleteDC(hSrcDC);
     DeleteDC(hMemDC);
     //返回位置句柄
     return hBitmap;
}
BOOL SaveCapturedBitmap(HBITMAP hBitmap, CString FileName)
{
     if(hBitmap==NULL || FileName.IsEmpty())
     {
      AfxMessageBox("参数错误");
      return false;
     }

     HDC hDC;
     //当前分辨率下每象素所占字节数
     int iBits;
     //位图中每象素所占字节数
     WORD wBitCount;
     //定义调色板大小，位图中像素字节大小，位图文件大小，写入文件字节数
     DWORD dwPaletteSize=0, dwBmBitsSize=0, dwDIBSize=0, dwWritten=0;
     //位图属性结构
     BITMAP Bitmap;
     //位图文件头结构
     BITMAPFILEHEADER bmfHdr;
     //位图信息头结构
     BITMAPINFOHEADER bi;
     //指向位图信息头结构
     LPBITMAPINFOHEADER lpbi;
     //定义文件，分配内存句柄，调色板句柄
     HANDLE fh, hDib, hPal,hOldPal=NULL;

     //计算位图文件每个像素所占字节数
&n

补充：软件开发 , C++ ,