The Choices class is directly used only by GrammarBuilder objects.

A Choices object allows an application or developer to create a Grammar from a GrammarBuilder which can recognize audio input where one part of a phrase can have several values.

For example, a GrammarBuilder that supporting recognizing the phrase "Change color to [color]", where "[color]" can be any one of a list of values, would use an instance of Choices to define the acceptable values of "[color]".

The Choices class is analogous in its use to the SrgsOneOf member of the name space, or the one-of XML element under the Speech Recognition Grammar Specification (SRGS) name space.

The example below creates a Choices object (colorChoice) containing a list of all colors supported by the system. The Choices is then appended to the phrase "Set Background to" and a Grammar is created, which will recognize input of the form "Set background to [color]", where color could be any of the names of the members of the enumeration, such as "red", "blue", and "ActiveBorder".

private Grammar CreateSimpleColorGrammar(params int[] info) {
    
    Choices colorChoice = new Choices();      // Associate the string 
    foreach (string colorName in System.Enum.GetNames(typeof(KnownColor))) {
        // Associate the string name of the color with each item.
        colorChoice.Add(colorName);
    }
    GrammarBuilder builder1 = new GrammarBuilder("Set Background to");
    builder1.Append(colorChoice);
    Grammar grammar = new Grammar(builder1);
    grammar.Name = "Set Background to";
    if (info.Length >= 1) {
        grammar.Priority = info[0];
    }
    return grammar;
}

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

.NET Framework

Reference

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