语音识别语义解释UWP

Question

我不明白为什么尽管SpeechResult是正确的，但返回给布尔值以启动动作的布尔值返回false，对我来说grammar.xaml似乎是正确的，但随后SemanticInterpretation将其返回错误。

MainPage.cs：

    public MainPage()
    {
        this.InitializeComponent();
        this.Loaded += OnLoaded;

        this.actions = new Dictionary<string, Dictionary<string, Action>>()
        {
            [ASCOLTO_RULE] = new Dictionary<string, Action>()
            {
                [ASCOLTO_OPTION] = OnGreen,
            },
        };
    }

    private void OnGreen()
    {
        Background = new SolidColorBrush(Colors.Green);
    }

    async void OnLoaded(object sender, RoutedEventArgs e)
    {
        this.speechRecognizer = new SpeechRecognizer();
        this.speechRecognizer.Timeouts.BabbleTimeout = TimeSpan.FromSeconds(0);
        this.speechRecognizer.Timeouts.InitialSilenceTimeout = TimeSpan.FromSeconds(0);
        this.speechRecognizer.Timeouts.EndSilenceTimeout = TimeSpan.FromSeconds(0);

        var grammarFile = await StorageFile.GetFileFromApplicationUriAsync(
          new Uri("ms-appx:///grammar.xml"));

        this.speechRecognizer.Constraints.Add(
          new SpeechRecognitionGrammarFileConstraint(grammarFile));

        var result = await speechRecognizer.CompileConstraintsAsync();

        if (result.Status == SpeechRecognitionResultStatus.Success)
        {
            while (true)
            {
                var speechResult = await speechRecognizer.RecognizeAsync();

                if ((speechResult.Confidence == SpeechRecognitionConfidence.Medium) ||
                  (speechResult.Confidence == SpeechRecognitionConfidence.High))
                {
                    string spokenCommand = string.Empty;

                    var lastRulePath = speechResult.RulePath.Last();
                    IReadOnlyList<string> values = null;

                    if (speechResult?.SemanticInterpretation?.Properties.TryGetValue(
                      ACTION_IDENTIFIER, out values) == (bool)true)
                    {
                        var action = values.FirstOrDefault();

                        // Ok, we have a rule and an action. Need to execute on it.
                        this.actions[lastRulePath]?[action]?.Invoke();
                    }
                }
            }
        }
    }

    SpeechRecognizer speechRecognizer;
    Dictionary<string, Dictionary<string, Action>> actions;

    static readonly string ASCOLTO_RULE = "avviaascolto";
    static readonly string ASCOLTO_OPTION = "avviacomandovocale";
    static readonly string ACTION_IDENTIFIER = "action";

    static readonly int TRANSLATION = 100;
    static readonly float SCALE = 0.5f;

grammar.xml：

<?xml version="1.0" encoding="utf-8"?>
<grammar
  version="1.0" mode="voice" root="comando"
  xml:lang="it-IT" tag-format="semantics/1.0"
  xmlns="http://www.w3.org/2001/06/grammar">

  <rule id="comando">
    <one-of>
      <item>
        <ruleref uri="#avviaascolto"/>
      </item>
    </one-of>
  </rule>

  <rule id="avviaascolto">
    <one-of>
      <item>
        <tag>out="ascoltoavviato";</tag>
        avvia ascolto
        <tag> out.action="avviacomandovocale"; </tag>
      </item>
    </one-of>
  </rule>

</grammar>

我想了解的是错误在哪里，如果是grammar.xaml或后面的代码中。

预先感谢