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RecognizerUpdateReachedEventArgs Class

System.Object
  System.EventArgs
    System.Speech.Recognition.RecognizerUpdateReachedEventArgs

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

public class RecognizerUpdateReachedEventArgs : EventArgs

The RecognizerUpdateReachedEventArgs type exposes the following members.

  NameDescription
Public propertyAudioPositionGets the audio position associated with the event.
Public propertyUserTokenGets the UserToken passed to the system when an application calls RequestRecognizerUpdate or RequestRecognizerUpdate.
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  NameDescription
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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RecognizerUpdateReached events provide a mechanism for pausing a speech recognition engine to apply atomic and synchronous modifications, such as loading and unloading grammars.

If your application is using a SpeechRecognitionEngine instance to manage recognition, it can use one of the SpeechRecognitionEngine.RequestRecognizerUpdate methods to request that the engine pauses to receive an update. The SpeechRecognitionEngine instance raises a SpeechRecognitionEngine.RecognizerUpdateReached event when it is ready for the update.

While a SpeechRecognitionEngine instance is paused, you can load, unload, enable, and disable Grammar objects, and modify values for the BabbleTimeout, InitialSilenceTimeout, and EndSilenceTimeout properties.

If your application is using a SpeechRecognizer instance to manage recognition, it can use one of the SpeechRecognizer.RequestRecognizerUpdate methods to request that the engine pauses to receive an update. The SpeechRecognizer instance raises a SpeechRecognizer.RecognizerUpdateReached event when it is ready for the update.

While a SpeechRecognizer instance is paused, you can load, unload, enable, and disable Grammar objects.

When handling SpeechRecognitionEngine.RecognizerUpdateReached and SpeechRecognizer.RecognizerUpdateReached events, a recognition engine pauses until the event handler returns.

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

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

      // Initialize an in-process speech recognition engine and configure its input.
      using (recognizer = new SpeechRecognitionEngine(new System.Globalization.CultureInfo("en-US")))
      {
        recognizer.SetInputToDefaultAudioDevice();

        // 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.
        recognizer.LoadGrammar(farmAnimals);

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

        // Pause to recognize farm animals.
        Thread.Sleep(7000);
        Console.WriteLine();

        // Request an update and load the Fruit grammar.
        recognizer.RequestRecognizerUpdate();
        recognizer.LoadGrammarAsync(favoriteFruit);
        Thread.Sleep(7000);

        // Request an update and unload the Farm grammar.
        recognizer.RequestRecognizerUpdate();
        recognizer.UnloadGrammar(farmAnimals);
        Thread.Sleep(7000);
      }

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

    // 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();
      Console.WriteLine("Update reached:");
      Thread.Sleep(1000);

      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");
    }
  }
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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