GrammarBuilder Constructor (GrammarBuilder, Int32, Int32)


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Initializes a new instance of the GrammarBuilder class from a repeated element.

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

public GrammarBuilder(
	GrammarBuilder builder,
	int minRepeat,
	int maxRepeat


Type: System.Speech.Recognition.GrammarBuilder

The repeated element.

Type: System.Int32

The minimum number of times that input matching the element defined by builder must occur to constitute a match.

Type: System.Int32

The maximum number of times that input matching the element defined by builder can occur to constitute a match.

If the value of minRepeat is 0, then the new GrammarBuilder represents an optional element.

The value of minRepeat must be greater than or equal to 0 and less than or equal to the value of maxRepeat.


When you specify repeats for GrammarBuilder objects that contain SemanticResultValue or SemanticResultKey instances, make sure you avoid creating duplicate semantic elements with the same key name or multiple semantic elements that could repeatedly modify the Value property of a SemanticValue object. The speech recognizer can throw an exception if it encounters these circumstances. For more information about building a speech recognition grammar that contains semantic information, see Using SemanticResultKey and SemanticResultValue Objects.

The following example creates a speech recognition grammar for ordering a pizza. It starts with an optional, opening phrase, followed by one to four toppings, and closes with the word "pizza".

private static Grammar CreatePizzaGrammar()

  // Create a Choices object from a string array of alternative toppings.
  Choices toppings = new Choices(new string[] {
    "cheese", "mushroom", "tomato", "onion",
    "anchovy", "chicken", "pepperoni"});

  // Create a GrammarBuilder and append the Choices object.
  GrammarBuilder andToppings = new GrammarBuilder("and", 0, 1);

  // Construct the phrase.
  GrammarBuilder gb = new GrammarBuilder("I would like a", 0, 1);
  gb.Append(new GrammarBuilder(andToppings, 0, 3));

  // Create the Grammar from the GrammarBuilder.
  Grammar grammar = new Grammar(gb);
  grammar.Name = "Pizza Order";

  return grammar;

.NET Framework
Available since 3.0
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