RecognizerUpdateReachedEventArgs Class

Provides data for the RecognizerUpdateReached event.

Inheritance Hierarchy


Namespace:  Microsoft.Speech.Recognition
Assembly:  Microsoft.Speech (in Microsoft.Speech.dll)


Public Class RecognizerUpdateReachedEventArgs _
    Inherits EventArgs
Dim instance As RecognizerUpdateReachedEventArgs
public class RecognizerUpdateReachedEventArgs : EventArgs


An instance of RecognizerUpdateReachedEventArgs is created when the SpeechRecognitionEngine object raises the RecognizerUpdateReached event at the completion of a RequestRecognizerUpdate() method.

You use the RequestRecognizerUpdate() methods to request the SpeechRecognitionEngine to pause. When the RecognizerUpdateReached event is raised, you can use the handler for the event to make modifications to the paused SpeechRecognitionEngine instance.

For example, while the SpeechRecognitionEngine is paused, you can load, unload, enable, and disable Grammar objects, and modify values for the BabbleTimeout, InitialSilenceTimeout, and EndSilenceTimeout properties. When handling SpeechRecognitionEngine.RecognizerUpdateReached events, a recognition engine pauses until the event handler returns.

For more information, see the RequestRecognizerUpdate method.

SpeechRecognitionRejectedEventArgs derives from EventArgs.


The following example shows a console application that loads and unloads Grammar objects. The application uses the RequestRecognizerUpdate() method to request the speech recognition engine to pause so it can receive an update. The application then loads or unloads a Grammar object.

At each update, a handler for SpeechRecognitionEngine.RecognizerUpdateReached event writes the name and status of the currently loaded Grammar objects to the console. As grammars are loaded and unloaded, the application first recognizes the names of farm animals, then the names of farm animals and the names of fruits, then only the names of fruits.

using System;
using Microsoft.Speech.Recognition;
using System.Collections.Generic;
using System.Threading;

namespace SampleRecognition
  class Program
    private static SpeechRecognitionEngine recognizer;
    public static void Main(string[] args)

      // Initialize a SpeechRecognitionEngine object and configure its input.
      using (recognizer = new SpeechRecognitionEngine(new System.Globalization.CultureInfo("en-US")))

        // Create the first grammar - Farm.
        Choices animals = new Choices(new string[] { "cow", "pig", "goat" });
        GrammarBuilder farm = new GrammarBuilder(animals);
        Grammar farmAnimals = new Grammar(farm);
        farmAnimals.Name = "Farm";

        // Create the second grammar - Fruit.
        Choices fruit = new Choices(new string[] { "apples", "peaches", "oranges" });
        GrammarBuilder favorite = new GrammarBuilder(fruit);
        Grammar favoriteFruit = new Grammar(favorite);
        favoriteFruit.Name = "Fruit";

        // Attach event handlers.
        recognizer.SpeechRecognized +=
          new EventHandler<SpeechRecognizedEventArgs>(recognizer_SpeechRecognized);
        recognizer.RecognizerUpdateReached +=
          new EventHandler<RecognizerUpdateReachedEventArgs>(recognizer_RecognizerUpdateReached);
        recognizer.SpeechRecognitionRejected +=
          new EventHandler<SpeechRecognitionRejectedEventArgs>(recognizer_SpeechRecognitionRejected);

        // Load the Farm grammar.

        // Start asynchronous, continuous recognition.
        Console.WriteLine("Starting asynchronous, continuous recognition");
        Console.WriteLine("  Farm grammar is loaded and enabled.");

        // Pause to recognize farm animals.

        // Request an update and load the Fruit grammar.

        // Request an update and unload the Farm grammar.

      // Keep the console window open.
      Console.WriteLine("Press any key to exit...");

    // At the update, get the names and enabled status of the currently loaded grammars.
    public static void recognizer_RecognizerUpdateReached(
      object sender, RecognizerUpdateReachedEventArgs e)
      Console.WriteLine("Update reached:");

      string qualifier;
      List<Grammar> grammars = new List<Grammar>(recognizer.Grammars);
      foreach (Grammar g in grammars)
        qualifier = (g.Enabled) ? "enabled" : "disabled";
        Console.WriteLine("  {0} grammar is loaded and {1}.",
        g.Name, qualifier);

    // Write the text of the recognized phrase to the console.
    static void recognizer_SpeechRecognized(object sender, SpeechRecognizedEventArgs e)
      Console.WriteLine("    Speech recognized: " + e.Result.Text);

    // Write a message to the console when recognition fails.
    static void recognizer_SpeechRecognitionRejected(object sender, SpeechRecognitionRejectedEventArgs e)
      Console.WriteLine("    Recognition attempt failed");

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also


RecognizerUpdateReachedEventArgs Members

Microsoft.Speech.Recognition Namespace