问BackgroundWorker DisconnectedContext

EN

public static Emgu.CV.Capture _capture;
public static DispatcherTimer _timer;

_timer = new DispatcherTimer();
_timer.Interval = _settings.camera_interval;
_timer.Tick += ProcessFrame;

BacgroundWorker _bw = new BackgroundWorker
{
    WorkerReportsProgress = true,
    WorkerSupportsCancellation = true
};

_bw.DoWork += (s, e) =>
{
    // Initialize the device in background
    _capture = new Capture();
};

_bw.RunWorkerCompleted += (s, e) =>
{
    _capture.SetCaptureProperty(CAP_PROP.CV_CAP_PROP_FRAME_HEIGHT,
        _settings.camera_height);
    _capture.SetCaptureProperty(CAP_PROP.CV_CAP_PROP_FRAME_WIDTH,
        _settings.camera_width);
    Brightness = _capture
        .GetCaptureProperty(CAP_PROP.CV_CAP_PROP_BRIGHTNESS);

    Contrast = _capture
        .GetCaptureProperty(CAP_PROP.CV_CAP_PROP_CONTRAST);

    // Get images from camera
    _timer.Start();
};

_bw.RunWorkerAsync();

 public override void CleanUp()
 {
     _timer.Stop();            
     _bw.Dispose();
     if (_capture != null) _capture.Dispose();
 }