双缓冲问题！

得到图形文件的头信息保存头信息就可以还原了,
我这有一个抓当前屏幕然后提取图片信息保存在本地硬盘程序你可以看下,应该有帮助:相关代码片段，将其置于View类中即可，楼主参考一下BITMAPINFObi;//信息头
void *pBits=NULL;
CRect rect;//客户区窗口
GetClientRect(&rect);
int nWidth=rect.right;
int nHeight=rect.bottom;
//填充信息头
ZeroMemory(&bi,sizeof(bi));
bi.bmiHeader.biSize=sizeof(bi.bmiHeader);
bi.bmiHeader.biHeight=nHeight;
bi.bmiHeader.biWidth=nWidth;
bi.bmiHeader.biPlanes=1;
bi.bmiHeader.biBitCount=24;
bi.bmiHeader.biCompression=BI_RGB;
bi.bmiHeader.biSizeImage=3*nWidth*nHeight;//拷贝客户区至内存DC
HDC hActiveDC=::GetDC(this);
HDC hActiveWndCompatibleDC=CreateCompatibleDC(hActiveDC);
HDC hActiveWndCompactibleBitmap=CreateCompatibleBitmap(hActiveDC,rect.right,rect.bottom);
SelectObject(hActiveWndCompatibleDC,hActiveWndCompactibleBitmap);//保存内存DC
HDChBmpFileDC=CreateCompatibleDC(hActiveWndCompatibleDC);
HBITMAPhBmpFileBitmap=CreateDIBSection(hActiveWndCompatibleDC,&bi,DIB_RGB_COLORS,&pBits,NULL,0);
SelectObject(hBmpFileDC,hBmpFileBitmap);
BitBlt(hBmpFileDC,0,0,nWidth,nHeight,hActiveWndCompatibleDC,0,0,SRCCOPY);CString tempFileName;//目标文件名
HANDLEhFile=CreateFile(tempFileName,GENERIC_WRITE,FILE_SHARE_WRITE,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
if(hFile!=INVALID_HANDLE_VALUE)
{
DWORDdwRet=0;
//填充文件头
BITMAPFILEHEADERbmfHeader;
ZeroMemory(&bmfHeader,sizeof(bmfHeader));
bmfHeader.bfOffBits=sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER);
bmfHeader.bfSize=bi.bmiHeader.biSizeImage+bmfHeader.bfOffBits;
bmfHeader.bfType='MB';
WriteFile(hFile,&bmfHeader,sizeof(bmfHeader),&dwRet,NULL);
WriteFile(hFile,&bi.bmiHeader,sizeof(bi.bmiHeader),&dwRet,NULL);
WriteFile(hFile,pBits,bi.bmiHeader.biSizeImage,&dwRet,NULL);
CloseHandle(hFile);
}