在mfc中picture控件中显示Mat图片

void ShowMatImgToWnd(CWnd* pWnd, cv::Mat img)
{
if(img.empty())  
return;  

CRect drect;       
pWnd->GetClientRect(&drect);    //(drect);  (&drect);  两种方式均可，竟然

CClientDC dc(pWnd);
HDC hDC =dc.GetSafeHdc();

//内存中的图像数据拷贝到屏幕上
BYTE *bitBuffer    = NULL;
BITMAPINFO *bitMapinfo = NULL;

int ichannels =img.channels();
if( ichannels == 1)
{
bitBuffer  = new BYTE[40+4*256]; 
}
else if( ichannels == 3)
{
bitBuffer  = new BYTE[sizeof(BITMAPINFO)]; 
}
else
{
return;
}