Android TextToSpeech: speak failed: not bound to TTS engine

Question

My TextToSpeech works fine on the first run, but it doesn't work after the application has been closed using "back" key and reopened. The error is TextToSpeech: speak failed: not bound to TTS engine and status in onInit is ERROR

I have a class to handle TTS:

public class VoiceGenerator {
    public TextToSpeech tts;
    private Context context;
    private String TAG = "Voice Generator";

    private static VoiceGenerator instance;

    private VoiceGenerator(Context context){
        this.context = context;
    }

    public static VoiceGenerator getInstance(Context context){
        if (instance == null) {
            instance = new VoiceGenerator(context);
        }

        return instance;
    }

    public void initializeTTS() {
        if (tts == null) {
            Log.d(TAG, "initialize tts");
            tts = new TextToSpeech(context, new TextToSpeech.OnInitListener() {
                @Override
                public void onInit(int status) {
                    if (status != TextToSpeech.ERROR) {
                        Log.d(TAG, "initialize tts success");
                        tts.setLanguage(...);                           
                    }      
                }
            });    
        }
    }

    public void speak(){
        tts.speak(...)
    }

    public void shutdown(){
        if(tts != null) {   
            tts.stop();
            tts.shutdown();
            tts=null;
            Log.d(TAG, "TTS Destroyed");
        }
    }

}

I get the instance of VoiceGenerator in onCreate:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);   
    voiceGenerator = VoiceGenerator.getInstance(this);
}

Initialize TTS in onStart:

@Override
protected void onStart(){
    super.onStart();
    voiceGenerator.initializeTTS();
}

And shut it down in onDestroy:

@Override
protected void onDestroy() {
super.onDestroy();
voiceGenerator.shutdown();    
}

Any ideas on what I am doing wrong?

Answer 1

You need to implement TextToSpeech.OnInitListener on the MainActivity . Here's a good example.

Code:

public class MainActivity extends ActionBarActivity  implements TextToSpeech.OnInitListener{

    private TextToSpeech engine;
    private EditText text;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        text = (EditText) findViewById(R.id.text);
        engine = new TextToSpeech(this, this);
    }



    public void speakText(View v) {

        String textContents = text.getText().toString();
        engine.speak(textContents, TextToSpeech.QUEUE_FLUSH, null, null);

    }

    @Override
    public void onInit(int i) {


        if (i == TextToSpeech.SUCCESS) {
            //Setting speech Language
            engine.setLanguage(Locale.ENGLISH);
            engine.setPitch(1);
        }
    }

}

Answer 2

Use onResume

@Override
protected void onResume() {
super.onResume();
myTTS = new TextToSpeech(this, this);
     }
}

Answer 3

简单的解决方案，并非所有设备都支持 TextToSpeach ，尝试使用不同的设备，

Answer 4

You can only let the engine speak, after onInit is done, so do following in onInit():

   if (status == TextToSpeech.SUCCESS) {
     tts.speak("Hello World", TextToSpeech.QUEUE_FLUSH, null);      

   }