mfc +opencv 读取图片显示到对话框

int ShowMat(cv::Mat img, HWND hWndDisplay)
{
	if (img.channels() < 3)
	{
		return -1;
	}

	//构造将要显示的Mat版本图片  
	RECT rect;
	::GetClientRect(hWndDisplay, &rect);
	cv::Mat imgShow(abs(rect.top - rect.bottom), abs(rect.right - rect.left), CV_8UC3);
	resize(img, imgShow, imgShow.size());

	//在控件上显示要用到的CImage类图片  
	ATL::CImage CI;
	int w = imgShow.cols;//宽    
	int h = imgShow.rows;//高    
	int channels = imgShow.channels();//通道数    
	CI.Create(w, h, 8 * channels);

	//CI像素的复制  
	uchar* pS;
	uchar* pImg = (uchar*)CI.GetBits();//得到CImage数据区地址    
	int step = CI.GetPitch();
	for (int i = 0;i < h;i++)
	{
		pS = imgShow.ptr<uchar>(i);
		for (int j = 0;j < w;j++)
		{
			for (int k = 0;k < 3;k++)
				*(pImg + i * step + j * 3 + k) = pS[j * 3 + k];
			//注意到这里的step不用乘以3    
		}
	}

	//在控件显示图片  
	HDC dc;
	dc = ::GetDC(hWndDisplay);
	CI.Draw(dc, 0, 0);
	::ReleaseDC(hWndDisplay, dc);
	CI.Destroy();

	return 0;
}

void CmfcimageDlg::OnBnClickedOpenimg()
{
	// TODO: 在此添加控件通知处理程序代码  
	CString FilePath;

	CFileDialog FileDlg(TRUE);

	if (IDOK == FileDlg.DoModal())
	{
		//获取FileOpen对话框返回的路径名  
		FilePath = FileDlg.GetPathName();

		//GetPathName返回的是CString类型，要经过转换为string类型才能使用imread打开图片  
		std::string pathName(CW2A(FilePath.GetString()));
		//std::string pathName(FilePath.GetBuffer());

		//读取图片  
		cv::Mat orgImg = cv::imread(pathName);

		//显示图片  
		ShowMat(orgImg, GetDlgItem(IDC_PIC_SHOW)->GetSafeHwnd());
	}
}