RecognizerUpdateReachedEventArgs Class


Returns data from a RecognizerUpdateReached or a RecognizerUpdateReached event.

public ref class RecognizerUpdateReachedEventArgs : EventArgs
public class RecognizerUpdateReachedEventArgs : EventArgs
type RecognizerUpdateReachedEventArgs = class
    inherit EventArgs
Public Class RecognizerUpdateReachedEventArgs
Inherits 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")))  

        // 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");  


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.



Gets the audio position associated with the event.


Gets the UserToken passed to the system when an application calls RequestRecognizerUpdate or RequestRecognizerUpdate.



Determines whether the specified object is equal to the current object.

(Inherited from Object)

Serves as the default hash function.

(Inherited from Object)

Gets the Type of the current instance.

(Inherited from Object)

Creates a shallow copy of the current Object.

(Inherited from Object)

Returns a string that represents the current object.

(Inherited from Object)

Applies to

See also