使用相机API后应用程序降至30 FPS

Question

我的应用程序中实现了条形码扫描程序。 该应用程序始终以60 FPS运行。

在捕捉（相机激活和扫描）期间，帧速率降至30 fps。

捕获后，当我处理我初始化的所有内容时， 整个应用程序继续使用30 FPS。

如何在摄像机任务后恢复到60 FPS？

private DispatcherTimer _timer;

//Fields I need for scanning (ZXing)
private PhotoCameraLuminanceSource _luminance;
private MultiFormatReader _reader;

//The cam itself
private PhotoCamera _camera;

这是我在凸轮初始化时调用的内容。

private void OnPhotoCameraInitialized(object sender, CameraOperationCompletedEventArgs e)
{
    try
    {
        _camera.FlashMode = FlashMode.Off;
        int width = Convert.ToInt32(_camera.PreviewResolution.Width);
        int height = Convert.ToInt32(_camera.PreviewResolution.Height);

        _luminance = new PhotoCameraLuminanceSource(width, height);
        _reader = new MultiFormatReader();
        _reader.Hints = hints;

        Dispatcher.BeginInvoke(() =>
        {
            try
            {
                brushTransform.Rotation = _camera.Orientation;
                if (_timer != null) _timer.Start();

            }
            catch (Exception ex) { Debug.WriteLine(ex.Message); }
        });
    }
    catch {}
}

这是计时器的滴答方法

private void Scan()
{
    _camera.Focus();
    try
    {
        _camera.GetPreviewBufferY(_luminance.PreviewBufferY);
        var binarizer = new HybridBinarizer(_luminance);
        var binBitmap = new BinaryBitmap(binarizer);
        var result = _reader.decode(binBitmap);

        if (result != null)
        {
            FileManagement.saveFile("barcode", result.Text, null);
            goBack();
        }
    }
    catch (Exception ex)
    {
        Debug.WriteLine(ex.Message);
    }
}

这就是我最终回到搜索页面的方式

        private void goBack()
    {
        VibrateController.Default.Start(TimeSpan.FromMilliseconds(40));
        NavigationService.Navigate(new Uri("/MainPage.xaml", UriKind.Relative));
        customDispose();
    }

    protected override void OnBackKeyPress(System.ComponentModel.CancelEventArgs e)
    {
        base.OnBackKeyPress(e);
        customDispose();
    }

    private void customDispose()
    {
        _timer.Stop();
        _timer.Tick -= (o, arg) => Scan();
        _camera.Initialized -= OnPhotoCameraInitialized;
        _camera.Dispose();

        _camera = null;
        _reader = null;
        _luminance = null;
        _timer = null;
        GC.Collect();
    }