关于mfc多线程进度条的问题

protected:

	CWinThread* pThread;

UINT  ThreadSpeed(LPVOID lpParameter);//线程函数的声明  此行在类外

//下面是BOOL CVideoToPictureDlg::OnInitDialog()函数中关于初始化的代码：

m_ctrlProgress.SetRange(0,100);



	//设置进度条的每一步的增量



	m_ctrlProgress.SetStep(1);



	//设置进度条的当前位置



	m_ctrlProgress.SetPos(1);



	m_ctrlProgress.SendMessage(PBM_SETBKCOLOR, 0, RGB(255, 255, 255));//背景色



	m_ctrlProgress.SendMessage(PBM_SETBARCOLOR, 0, RGB(0, 255, 0));//前景色

 		waitKey(); 



	return TRUE; 



//下面是点击开始键的响应函数：

void CVideoToPictureDlg::OnBnClickedOk()

{

	// TODO: 在此添加控件通知处理程序代码

	if(infilename.IsEmpty())

	{

		MessageBox("请选择视频文件", "提示",MB_OK);

		return;

	}

	else if(outfilename.IsEmpty())

	{

		MessageBox("请选择输出文件夹", "提示",MB_OK);

		return;

	}

	CvCapture* capture = cvCreateFileCapture((LPSTR)(LPCTSTR)infilename);  

	IplImage* frame;  

	int i = 0;

	char image_name[20];

	CString Out;

	//pThread = AfxBeginThread(ThreadSpeed, &m_ctrlProgress);

	int numFrames = (int) cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_COUNT);

	while(1)  

	{  

		frame = cvQueryFrame(capture);  

		if(!frame) break ;  

		sprintf_s(image_name, "%s%d%s", "image", ++i, ".jpg");//保存的图片名  

		CString str3;

		str3.Format("%s",image_name);

		CString str2 = _T("\\");

		Out = outfilename + str2 + str3;

		cvSaveImage((LPSTR)(LPCTSTR)Out, frame);   //保存一帧图片  

		int jindu = (i * 100)/numFrames;

		percent = jindu;

		pThread = AfxBeginThread(ThreadSpeed, &m_ctrlProgress);//此处创建新线程



	}  



	MessageBox("已完成提取", "提示",MB_OK);

	cvReleaseCapture(&capture);  



}



//下面是线程函数

UINT ThreadSpeed(LPVOID lpParameter)

{

	CProgressCtrl *Speed = (CProgressCtrl*)lpParameter; 

	Speed->SetPos((percent));

	Sleep(10);

	return 0;

}