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SpeechRecognitionEngine.SpeechHypothesized Event

Event raised when when the recognition engine detects speech and part of the audio input speech has been tentatively recognized.

Namespace:  System.Speech.Recognition
Assembly:  System.Speech (in System.Speech.dll)
public event EventHandler<SpeechHypothesizedEventArgs> SpeechHypothesized

Handlers of SpeechHypothesized events can obtain the best possible hypothesis phrase through an instance of the RecognitionResult object returned by the Result property of the SpeechHypothesizedEventArgs object passed to the handler. (SpeechHypothesizedEventArgs is derived from[T:System.Speech.Recognition.SpeechRecognitionEventArgs)]).

Handlling of SpeechHypothesized is not typically required in production running, but is useful when debugging grammars.

The example below shows the subscription of an anonymous method as a handler for SpeechHypothesized, which in turn calls a display function (DisplayResult) to return to the user interface the best candidate and the list of alternates generated.

_recognizer.SpeechHypothesized +=
delegate(object sender, SpeechHypothesizedEventArgs eventArgs) {

    Utils.DisplayAudioInputFormat(_audioStateLabel, _recognizer);
            DisplayResult(eventArgs);
};

// Displays the semantics, rules, and alternates of the result.
private void DisplayResult(EventArgs eventArgs) {

    //Make sure We handle different event types we support
     RecognitionResult result=null;
    if (null !=(eventArgs as RecognitionEventArgs)) {
result = (eventArgs as RecognitionEventArgs).Result;
    }else if (null !=(eventArgs as EmulateRecognizeCompletedEventArgs)) {
result = (eventArgs as EmulateRecognizeCompletedEventArgs).Result;
    }

    // In all cases, clear results, semantic XML, semantics tree, and alternates.
    _recognitionSmlBrowser.Navigate("about:blank");
    _semanticsTreeView.Nodes.Clear();
    //            _candidateList.Items.Clear();
    _candidateList.DataSource = null;
    _candidateList.DisplayMember = null;
    _phraseInfoLabel.Text = "";
    _bestCandidateTextBox.Text = "";

    if (result != null) {
//If eventArgs not null repopulate displays
//Obtain result from RecognitionEventArg passed in.
//Set Text color on the basis of the event type passed in.

switch (eventArgs.GetType().ToString()) {

    case "System.Speech.Recognition.SpeechHypothesizedEventArgs":
        _bestCandidateTextBox.ForeColor = Color.Black;
        _bestCandidateTextBox.Text = result.Text;
        _phraseInfoLabel.Text = null;
        break;
    case "System.Speech.Recognition.SpeechRecognitionRejectedEventArgs":
        _bestCandidateTextBox.ForeColor = Color.OrangeRed;
        _bestCandidateTextBox.Text = "Unable to Recognize Input";
        _phraseInfoLabel.Text = String.Format("Rejected Phrase Information\n");
        Utils.DisplayBasicPhraseInfo(_phraseInfoLabel, result);
        Utils.DisplaySemanticsSML(_recognitionSmlBrowser, result);
        Utils.DisplaySemanticsTreeView(_semanticsTreeView, result.Semantics);
        break;
    case "System.Speech.Recognition.SpeechRecognizedEventArgs":
        _bestCandidateTextBox.ForeColor = Color.Green;
        _bestCandidateTextBox.Text = result.Text;
        _phraseInfoLabel.Text = String.Format("Recognized Phrase Information\n");
        Utils.DisplayBasicPhraseInfo(_phraseInfoLabel, result);
        Utils.DisplaySemanticsSML(_recognitionSmlBrowser, result);
        Utils.DisplaySemanticsTreeView(_semanticsTreeView, result.Semantics);
        break;
    case "System.Speech.Recognition.EmulateRecognizeCompletedEventArgs":
        _bestCandidateTextBox.ForeColor = Color.Green;
        _bestCandidateTextBox.Text = result.Text;
        _phraseInfoLabel.Text = String.Format("Recognized Phrase Information\n");
        Utils.DisplayBasicPhraseInfo(_phraseInfoLabel, result);
        Utils.DisplaySemanticsSML(_recognitionSmlBrowser, result);
        Utils.DisplaySemanticsTreeView(_semanticsTreeView, result.Semantics);
        break;
    default:
        _bestCandidateTextBox.ForeColor = Color.Black;
        break;
}

Utils.DisplayDataOnListBox(_candidateList, result.Alternates, "Text");

    }
}

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0
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