Grammar Constructor (Stream^)
Assembly: System.Speech (in System.Speech.dll)
Parameters
- stream
-
Type:
System.IO::Stream^
A stream that describes a speech recognition grammar in a supported format.
| Exception | Condition |
|---|---|
| ArgumentException | stream describes a grammar that does not contain a root rule. |
| ArgumentNullException | stream is null. |
| FormatException | The stream does not contain a valid description of a grammar, or describes a grammar that contains a rule reference that cannot be resolved. |
This constructor does not pass any parameters to the initialization handler, and the description should not define an initialization handler that requires arguments.
This constructor can create a Grammar instance from the following formats:
XML-format files that conform to the W3C Speech Recognition Grammar Specification (SRGS) Version 1.0
Grammars that have been compiled to a binary file with a .cfg file extension
This constructor compiles XML-format grammar files to a binary format to optimize them for loading and consumption by a speech recognition engine. You can reduce the amount of time required to construct a Grammar object from an XML-format grammar by compiling the grammar in advance, using one of the Compile methods.
An SRGS grammar can define a root rule. To create a Grammar object from a stream and specify a root rule, use the Grammar or Grammar constructor.
To create a Grammar object from a stream and specify a base URI to use to resolve relative rule references, use the Grammar constructor.
The following example creates a speech recognition grammar from a local SRGS file (cities.xml) using a file stream. The content of the cities.xml file appears following C# example.
// Load a cities grammar from an I/O stream and // return the new grammar. private static Grammar CreateGrammarFromStream() { string fileName = @"c:\temp\cities.xml"; Grammar citiesGrammar = new Grammar(new FileStream(fileName, FileMode.Open)); citiesGrammar.Name = "Stream Cities Grammar"; return citiesGrammar; }
<?xml version="1.0" encoding="UTF-8" ?> <grammar version="1.0" xml:lang="en-US" xmlns="http://www.w3.org/2001/06/grammar" tag-format="semantics/1.0" root="Main"> <!-- cities.xml: Defines an SRGS grammar for requesting a flight. This grammar includes a Cities rule that lists the cities that can be used for departures and destinations. --> <rule id="Main"> <item> I would like to fly from <ruleref uri="#Cities"/> to <ruleref uri="#Cities"/> </item> </rule> <rule id="Cities" scope="public"> <one-of> <item>Seattle</item> <item>Los Angeles</item> <item>New York</item> <item>Miami</item> </one-of> </rule> </grammar>
Available since 3.0