Question

有人可以提供帮助。当我通过单击按钮调用RequestDeviceAccess时，它总是返回false。

这是代码

public partial class MainPage：UserControl { private AudioCaptureDevice _audioDevice; private CaptureSource _captureSource; private AudioFormat _format; private MemoryAudioSink _sink;

    public MainPage()
    {
        InitializeComponent();

        _audioDevice = CaptureDeviceConfiguration.GetDefaultAudioCaptureDevice();

        if (_audioDevice == null)
        {
            return;
        }

        _captureSource = new CaptureSource() { AudioCaptureDevice = _audioDevice };
        _format = _captureSource.AudioCaptureDevice.SupportedFormats.FirstOrDefault(p => p.WaveFormat == WaveFormatType.Pcm && p.BitsPerSample == 16 && p.SamplesPerSecond == 8000 && p.Channels == 1);
        _captureSource.AudioCaptureDevice.DesiredFormat = _format;
    }

    private bool EnsureAudioAccess()
    {
        return CaptureDeviceConfiguration.AllowedDeviceAccess || CaptureDeviceConfiguration.RequestDeviceAccess();
    }

    private void btnStartCapture_Click(object sender, RoutedEventArgs e)
    {
        if (!EnsureAudioAccess()) return;

        _sink = new MemoryAudioSink();
        _sink.CaptureSource = _captureSource;
        _captureSource.Start();

        this.media1.SetSource(_sink.BackingStream);
        this.media1.Play();
    }

}

Answer 1

我遇到了同样的问题，并通过删除在以下验证之前设置的所有断点进行排序：

return CaptureDeviceConfiguration.AllowedDeviceAccess || CaptureDeviceConfiguration.RequestDeviceAccess();

尝试调用saveFileDialog.ShowDialog（）方法时，我也遇到了类似的问题，并设置了断点。删除了断点和瞧。

希望它有所帮助！

Answer 2

在调试模式下，它总是返回false。在Release上运行项目。 Ctrl + F5

Answer 3

根据Silverlight.net网站，必须调用CaptureDeviceConfiguration（）以响应用户启动的事件，例如点击按钮：

http://www.silverlight.net/learn/graphics/webcam-and-mic/webcams-(silverlight-quickstart）

Silverlight 4 RequestDeviceAccess（）始终返回null。没有对话

3 个答案: