XSpeechSynthesizerEnumerateInstalledVoices

Article
06/22/2023

Enumerates the installed voices, and calls the method pointed to by callback for each voice.

Syntax

HRESULT XSpeechSynthesizerEnumerateInstalledVoices(  
         void* context,  
         XSpeechSynthesizerInstalledVoicesCallback* callback  
)

Parameters

context _In_opt_
Type: void*

A user-specified variable that will be passed into the callback function to enable the caller to recover caller-specific data.

callback _In_
Type: XSpeechSynthesizerInstalledVoicesCallback*

A pointer to the method that will be called once per installed voice.

Return value

Type: HRESULT

Returns S_OK if successful; otherwise, returns an error code. For a list of error codes, see Error Codes.

Remarks

Note

This function isn't safe to call on a time-sensitive thread. For more information, see Time-sensitive threads.

This function enumerates over the speech synthesis engines, or voices, installed on the device. The function invokes the XSpeechSynthesizerInstalledVoicesCallback callback function specified in callback once for each installed voice, and it passes an XSpeechSynthesizerVoiceInformation structure that contains information about that voice.

The following example demonstrates how to call the XSpeechSynthesizerEnumerateInstalledVoices function to enumerate over the installed voices on the device. The example invokes the XSpeechSynthesizerInstalledVoicesCallback callback function to (1) count the number of voices installed on the device and to (2) output information about each installed voice from the XSpeechSynthesizerVoiceInformation structure to the debugger.

int Game::CountInstalledVoices()
{
    HRESULT hr = S_OK;
    int* voiceCount = new int();
    // Call XSpeechSynthesizerEnumerateInstalledVoices with a callback function
    // defined as a lambda expression that increments the count of installed voices 
    // each time it's invoked, and outputs information about each voice to the 
    // debugger for display.
    hr = XSpeechSynthesizerEnumerateInstalledVoices(voiceCount,
        [](
            _In_ const XSpeechSynthesizerVoiceInformation* information,
            _In_ void* context
            ) -> bool 
        {
        // Increment and update the count of installed voices.
        int* voiceCount = (int*)context;
        *voiceCount = *voiceCount + 1;
        CopyMemory(context, voiceCount, sizeof(int));

        // Output information about the current installed voice
        // to the debugger for display.
        char buffer[1000];
        int bufferLen;
        bufferLen = sprintf(buffer, "(%s) %s - %s, %s\n",
            information->VoiceId,
            information->Description,
            information->Gender == XSpeechSynthesizerVoiceGender::Male ? "Male" : "Female",
            information->Language);
        OutputDebugStringA(buffer);
      
        // Continue iterating through installed voices.
        // If this was set to false, the calling function would stop
        // enumerating installed voices.
        return true;
        }
    );

    // Return the count of installed voices.
    return *voiceCount;
}

Requirements

Header: XSpeechSynthesizer.h

Library: xgameruntime.lib

Supported platforms: Windows, Xbox One family consoles and Xbox Series consoles

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