如何在winform中使用OpenCVSharp將網路攝像頭視頻流顯示到Picturebox中？

我正在使用此類成功錄制網路攝像頭視頻。但是這段代碼的問題是，我無法將實時視頻顯示到圖片框中

using System;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;
using OpenCvSharp;
using OpenCvSharp.Extensions;
using Size = OpenCvSharp.Size;

namespace Video_capture_23_08_2022
{
    public class Recorder : IDisposable
    {
        private readonly VideoCaptureAPIs _videoCaptureApi = VideoCaptureAPIs.DSHOW;
        private readonly ManualResetEventSlim _threadStopEvent = new ManualResetEventSlim(false);
        private readonly VideoCapture _videoCapture;
        private VideoWriter _videoWriter;

        private Mat _capturedFrame = new Mat();
        private Thread _captureThread;
        private Thread _writerThread;
        //private OutputArray frame;

        private bool IsVideoCaptureValid => _videoCapture is not null && _videoCapture.IsOpened();

        public Recorder(int deviceIndex, int frameWidth, int frameHeight, double fps, PictureBox pictureBox)
        {
            _videoCapture = VideoCapture.FromCamera(deviceIndex, _videoCaptureApi);
            _videoCapture.Open(deviceIndex, _videoCaptureApi);

            _videoCapture.FrameWidth = frameWidth;
            _videoCapture.FrameHeight = frameHeight;
            _videoCapture.Fps = fps;

             // Custom Function to show the webcam view into picturebox  
            _videoCapture.Read(_capturedFrame);
            if (!(_capturedFrame.Empty()))
            { 
            pictureBox.Image = OpenCvSharp.Extensions.BitmapConverter.ToBitmap(_capturedFrame);

            }

        }

        /// <inheritdoc />
        public void Dispose()
        {
            GC.SuppressFinalize(this);
            Dispose(true);
        }

        ~Recorder()
        {
            Dispose(false);
        }

        protected virtual void Dispose(bool disposing)
        {
            if (disposing)
            {
                StopRecording();

                _videoCapture?.Release();
                _videoCapture?.Dispose();
            }
        }

        public void StartRecording(string path)
        {
            if (_writerThread is not null)
                return;

            if (!IsVideoCaptureValid)
                ThrowHelper.ThrowVideoCaptureNotReadyException();

            _videoWriter = new VideoWriter(path, FourCC.XVID, _videoCapture.Fps, new Size(_videoCapture.FrameWidth, _videoCapture.FrameHeight));

            _threadStopEvent.Reset();

            _captureThread = new Thread(CaptureFrameLoop);
            _captureThread.Start();

            _writerThread = new Thread(AddCameraFrameToRecordingThread);
            _writerThread.Start();
        }

        public void StopRecording()
        {
            _threadStopEvent.Set();

            _writerThread?.Join();
            _writerThread = null;

            _captureThread?.Join();
            _captureThread = null;

            _threadStopEvent.Reset();

            _videoWriter?.Release();
            _videoWriter?.Dispose();
            _videoWriter = null;
        }

        private void CaptureFrameLoop()
        {
            while (!_threadStopEvent.Wait(0))
            {
                _videoCapture.Read(_capturedFrame);
            }
        }

        private void AddCameraFrameToRecordingThread()
        {
            var waitTimeBetweenFrames = 1_000 / _videoCapture.Fps;
            var lastWrite = DateTime.Now;

            while (!_threadStopEvent.Wait(0))
            {
                if (DateTime.Now.Subtract(lastWrite).TotalMilliseconds < waitTimeBetweenFrames)
                    continue;
                lastWrite = DateTime.Now;
                _videoWriter.Write(_capturedFrame);
            }
        }

        public Bitmap GetFrameBitmap()
        {
            if (!IsVideoCaptureValid)
                ThrowHelper.ThrowVideoCaptureNotReadyException();

            using (Mat frame = new Mat())
                return !_videoCapture.Read(frame) ? null : frame.ToBitmap();
        }
    }
}

但我想稍微修改一下以將網路攝像頭視圖顯示到圖片框中，但是這個自定義部分

 // Custom Function to show the webcam view into picturebox  
 _videoCapture.Read(_capturedFrame);
 if (!(_capturedFrame.Empty()))
  { 
   pictureBox.Image = OpenCvSharp.Extensions.BitmapConverter.ToBitmap(_capturedFrame); 
  }

僅顯示靜止影像而不是實時視頻。請幫助我找出問題所在。

uj5u.com熱心網友回復：

您的實作中缺少的部分是您捕獲網路攝像頭影像并將其顯示在pictureBox建構式中，僅一次而不是CaptureFrameLoop()重復顯示。因此，您需要將此塊移動到CaptureFrameLoop().

_videoCapture.Read(_capturedFrame);
if (!(_capturedFrame.Empty()))
{ 
   pictureBox.Image = OpenCvSharp.Extensions.BitmapConverter.ToBitmap(_capturedFrame); 
}

此外，您應該使用從非 UI 執行緒Control.Invoke修改影像。PictureBox

private void CaptureFrameLoop()
{
   while (!_threadStopEvent.Wait(0))
   {
        _videoCapture.Read(_capturedFrame);
        if (!(_capturedFrame.Empty()))
        { 
            pictureBox.Invoke(new Action(() => pictureBox.Image = OpenCvSharp.Extensions.BitmapConverter.ToBitmap(_capturedFrame))); 
        }
   }
}

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