SpeechRecognitionEngine.EmulateRecognize Method (String)

 

Emulates input of a phrase to the speech recognizer, using text in place of audio for synchronous speech recognition.

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

public RecognitionResult EmulateRecognize(
	string inputText
)

Parameters

inputText
Type: System.String

The input for the recognition operation.

Return Value

Type: System.Speech.Recognition.RecognitionResult

The result for the recognition operation, or null if the operation is not successful or the recognizer is not enabled.

Exception Condition
InvalidOperationException

The recognizer has no speech recognition grammars loaded.

ArgumentNullException

inputText is null.

ArgumentException

inputText is the empty string ("").

The speech recognizer raises the SpeechDetected, SpeechHypothesized, SpeechRecognitionRejected, and SpeechRecognized events as if the recognition operation is not emulated.

The recognizers that ship with Vista and Windows 7 ignore case and character width when applying grammar rules to the input phrase. For more information about this type of comparison, see the CompareOptions enumeration values OrdinalIgnoreCase and IgnoreWidth. The recognizers also ignore new lines and extra white space and treat punctuation as literal input.

The code example below is part of a console application that demonstrates emulated input, the associated recognition results, and the associated events raised by the speech recognizer. The example generates the following output.

TestRecognize("Smith")...
 SpeechDetected event raised.
 SpeechRecognized event raised.
  Grammar = Smith; Text = Smith
...Recognition result text = Smith

TestRecognize("Jones")...
 SpeechDetected event raised.
 SpeechRecognized event raised.
  Grammar = Jones; Text = Jones
...Recognition result text = Jones

TestRecognize("Mister")...
 SpeechDetected event raised.
 SpeechHypothesized event raised.
  Grammar = Smith; Text = mister
 SpeechRecognitionRejected event raised.
  Grammar = <not available>; Text =
...No recognition result.

TestRecognize("Mister Smith")...
 SpeechDetected event raised.
 SpeechRecognized event raised.
  Grammar = Smith; Text = mister Smith
...Recognition result text = mister Smith

press any key to exit...

using System;
using System.Globalization;
using System.Speech.Recognition;

namespace Sre_EmulateRecognize
{
  class Program
  {
    static void Main(string[] args)
    {

      // Create an in-process speech recognizer for the en-US locale.
      using (SpeechRecognitionEngine recognizer =
        new SpeechRecognitionEngine(new CultureInfo("en-US")))
      {

        // Load grammars.
        recognizer.LoadGrammar(CreateNameGrammar("Smith"));
        recognizer.LoadGrammar(CreateNameGrammar("Jones"));

        // Disable audio input to the recognizer.
        recognizer.SetInputToNull();

        // Add handlers for events raised by the EmulateRecognize method.
        recognizer.SpeechDetected +=
          new EventHandler<SpeechDetectedEventArgs>(
            SpeechDetectedHandler);
        recognizer.SpeechHypothesized +=
          new EventHandler<SpeechHypothesizedEventArgs>(
            SpeechHypothesizedHandler);
        recognizer.SpeechRecognitionRejected +=
          new EventHandler<SpeechRecognitionRejectedEventArgs>(
            SpeechRecognitionRejectedHandler);
        recognizer.SpeechRecognized +=
          new EventHandler<SpeechRecognizedEventArgs>(
            SpeechRecognizedHandler);

        // Start four synchronous emulated recognition operations.
        TestRecognize(recognizer, "Smith");
        TestRecognize(recognizer, "Jones");
        TestRecognize(recognizer, "Mister");
        TestRecognize(recognizer, "Mister Smith");
      }

      Console.WriteLine("press any key to exit...");
      Console.ReadKey(true);
    }

    // Create a simple name grammar.
    // Set the grammar name to the surname.
    private static Grammar CreateNameGrammar(string surname)
    {
      GrammarBuilder builder = new GrammarBuilder("mister", 0, 1);
      builder.Append(surname);

      Grammar nameGrammar = new Grammar(builder);
      nameGrammar.Name = surname;

      return nameGrammar;
    }

    // Send emulated input to the recognizer for synchronous recognition.
    private static void TestRecognize(
      SpeechRecognitionEngine recognizer, string input)
    {
      Console.WriteLine("TestRecognize(\"{0}\")...", input);
      RecognitionResult result =
        recognizer.EmulateRecognize(input,CompareOptions.IgnoreCase);
      if (result != null)
      {
        Console.WriteLine("...Recognition result text = {0}",
          result.Text ?? "<null>");
      }
      else
      {
        Console.WriteLine("...No recognition result.");
      }
      Console.WriteLine();
    }

    static void SpeechDetectedHandler(
      object sender, SpeechDetectedEventArgs e)
    {
      Console.WriteLine(" SpeechDetected event raised.");
    }

    // Handle events.
    static void SpeechHypothesizedHandler(
      object sender, SpeechHypothesizedEventArgs e)
    {
      Console.WriteLine(" SpeechHypothesized event raised.");
      if (e.Result != null)
      {
        Console.WriteLine("  Grammar = {0}; Text = {1}",
          e.Result.Grammar.Name ?? "<none>", e.Result.Text);
      }
      else
      {
        Console.WriteLine("  No recognition result available.");
      }
    }

    static void SpeechRecognitionRejectedHandler(
      object sender, SpeechRecognitionRejectedEventArgs e)
    {
      Console.WriteLine(" SpeechRecognitionRejected event raised.");
      if (e.Result != null)
      {
        string grammarName;
        if (e.Result.Grammar != null)
        {
          grammarName = e.Result.Grammar.Name ?? "<none>";
        }
        else
        {
          grammarName = "<not available>";
        }
        Console.WriteLine("  Grammar = {0}; Text = {1}",
          grammarName, e.Result.Text);
      }
      else
      {
        Console.WriteLine("  No recognition result available.");
      }
    }

    static void SpeechRecognizedHandler(
      object sender, SpeechRecognizedEventArgs e)
    {
      Console.WriteLine(" SpeechRecognized event raised.");
      if (e.Result != null)
      {
        Console.WriteLine("  Grammar = {0}; Text = {1}",
          e.Result.Grammar.Name ?? "<none>", e.Result.Text);
      }
      else
      {
        Console.WriteLine("  No recognition result available.");
      }
    }
  }
}

.NET Framework
Available since 3.0
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