Windows Phone 8 语音识别异常

我正在开发Windows Phone 8应用程序。我在语音识别方面遇到问题。这是我的代码。

SpeechRecognizerUI recoWithUI= new SpeechRecognizerUI();
try
{
    this.recoWithUI = new SpeechRecognizerUI();
    // Start recognition (load the dictation grammar by default).
    SpeechRecognitionUIResult recoResult = await recoWithUI.RecognizeWithUIAsync();
    // Do something with the recognition result.
    MessageBox.Show(string.Format("You said {0}.", recoResult.RecognitionResult.Text));
}
catch (Exception)
{
    throw;
}

每次我运行它时，它都会转到 App.xaml.cs 类并指出这个问题

private void Application_UnhandledException(object sender, ApplicationUnhandledExceptionEventArgs e)
{
    if (Debugger.IsAttached)
    {
        // An unhandled exception has occurred; break into the debugger
        Debugger.Break(); // It focuses on this line.
    }
}

你知道如何解决这个问题吗？谢谢