GrammarBuilder::Addition Operator (GrammarBuilder^, Choices^)
Creates a new GrammarBuilder that contains a GrammarBuilder followed by a Choices.
Assembly: System.Speech (in System.Speech.dll)
Parameters
- builder
-
Type:
System.Speech.Recognition::GrammarBuilder^
The first grammar element.
- choices
-
Type:
System.Speech.Recognition::Choices^
The second grammar element, which represents a set of alternative elements.
Return Value
Type: System.Speech.Recognition::GrammarBuilder^Returns a GrammarBuilder for the sequence of the builder parameter followed by the choices parameter.
GrammarBuilder supports conversions from the following classes:
This method accepts the objects listed above for the builder parameter. For more information, see the Implicit operators.
Important |
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When you combine Choices and 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 Understanding SemanticResultValue and SemanticResultKey Objects. |
The following example creates a speech recognition grammar that can recognize the two phrases, "Make background color" and "Set background to color", where color is selected from a set of colors. Various types are used to build the final grammar, such as String, Choices, and GrammarBuilder objects.
private Grammar CreateColorGrammar() { // Create a set of color choices. Choices colorChoice = new Choices(new string[] { "red", "green", "blue" }); // Create grammar builders for the two versions of the phrase. GrammarBuilder makePhrase = (GrammarBuilder)"Make background" + colorChoice; GrammarBuilder setPhrase = "Set background to" + (GrammarBuilder)colorChoice; // Create a Choices for the two alternative phrases, convert the Choices // to a GrammarBuilder, and construct the grammar from the result. Choices bothChoices = new Choices(new GrammarBuilder[] { makePhrase, setPhrase }); GrammarBuilder bothPhrases = new GrammarBuilder(bothChoices); Grammar grammar = new Grammar(bothPhrases); grammar.Name = "backgroundColor"; return grammar; }
Available since 3.0
