为什么没生成视频文件，谁知道 ？

为什么没生成视频文件，谁知道 ？

        private void 抓取摄像头画面ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            VideoCapture vc1 = new VideoCapture(CaptureDevice.Any,0); 
            vc1.Open(0);
            //创建文件流
            VideoWriter vw1 = new VideoWriter();
            vw1.Open(string.Format("d://{0}.avi",DateTime.Now.ToString("yyyyMMddHHmmss"))
                , -1, vc1.Get(CaptureProperty.Fps), new OpenCvSharp.Size(vc1.Get(CaptureProperty.FrameWidth), vc1.Get(CaptureProperty.FrameHeight)));

            //视频流处理
            Mat frame=new Mat();//用于保存每一帧图像

            while (true)
            {
                vc1.Read(frame);
                if (frame.Empty())     //如果某帧为空则退出循环
                    break;

                pictureShow.Image = frame.ToBitmap();

                //保存到文件流
                vw1.Write(frame);
                Application.DoEvents();

                int c = Cv2.WaitKey(30);
                if (c == 27)//Esc键退出
                {
                    break;
                }
                if (!抓取摄像头画面ToolStripMenuItem.Checked)
                    break;
            }
            vw1.Release();
            vc1.Dispose();
        }