为什么不调用UtteranceProgressListener的函数？

Question

当我呼叫该类的speak函数时，将调用UtteranceProgressListener，但不会调用侦听器的方法，即onStart(),onDone()和onError()。

最终，我们要编写一段代码，可以暂停文本到语音，并使用播放暂停按钮从同一句子恢复。

package com.example.android.m_tour; 

import android.content.Intent; 
import android.speech.tts.TextToSpeech; 
import android.speech.tts.UtteranceProgressListener; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 
import android.widget.Toast; 


import com.wnafee.vector.MorphButton; 

import java.util.HashMap; 
import java.util.Locale; 

import static com.example.android.m_tour.R.id.mb; 


public class guide extends AppCompatActivity implements MorphButton.OnStateChangedListener { 

    private Button settingsButton; 
    private String data, s; 
    private TextView textView; 
    private static TextToSpeech textToSpeech; 

    //qr code scanner object 
    private MainActivity mainActivity; 
    private TTSsettings ttSsettings; 
    private MorphButton control; 
    private Locale loc; 
    private String pr[]; 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_guide); 
     control = (MorphButton) findViewById(mb); 
     mainActivity = new MainActivity(); 
     textView = (TextView) findViewById(R.id.textview); 
     textView.setText(mainActivity.getData()); 
     settingsButton = (Button) findViewById(R.id.settings); 
     ttSsettings = new TTSsettings(); 
     loc = new Locale("en_IN"); 

     control.setOnStateChangedListener(this); 
     settingsButton.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 

       Intent intent = new Intent(guide.this, TTSsettings.class); 
       startActivity(intent); 
       /*textToSpeech.stop(); 
       Intent intent = new Intent(); 
       intent.setAction("com.android.settings"); 
       intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
       startActivity(intent);*/ 
      } 
     }); 
     data = mainActivity.getData(); 
     onStart(); 

     textToSpeech = new TextToSpeech(this, new TextToSpeech.OnInitListener() { 
      @Override 
      public void onInit(int i) { 
       if (i == TextToSpeech.SUCCESS) { 
        //set language Locale to US 
        int result = textToSpeech.setLanguage(loc); 
        //check that is language locale available on device or supported 
        if (result == TextToSpeech.LANG_MISSING_DATA 
          || result == TextToSpeech.LANG_NOT_SUPPORTED) { 
         Toast.makeText(guide.this, "Leanguage not present", Toast.LENGTH_SHORT).show(); 
        } else { 
         speakOut(); 
        } 

       } else { 
        //show toast if initialization failed 
        Toast.makeText(getBaseContext(), "TTS Engine Initilization Failed!", Toast.LENGTH_SHORT).show(); 
       } 

       textToSpeech.setOnUtteranceProgressListener(new UtteranceProgressListener() { 
        @Override 
        public void onStart(String s) { 
         //if ("id".equals(s) 
         Toast.makeText(guide.this, "onStart works", Toast.LENGTH_SHORT).show(); 

        } 

        @Override 
        public void onDone(String s) { 
         //if ("id".equals(s)) 
          Toast.makeText(guide.this, "onDone works", Toast.LENGTH_SHORT).show(); 
        } 

        @Override 
        public void onError(String s) { 
         //if ("id".equals(s)) 
          Toast.makeText(guide.this, "OnError works", Toast.LENGTH_SHORT).show(); 
        } 
       }); 

      } 
     }); 
    } 

    @Override 
    public void onDestroy() { 
     // Don't forget to stop and shutdown text to speech engine! 
     if (textToSpeech != null) { 
      textToSpeech.stop(); 
      textToSpeech.shutdown(); 
     } 
     super.onDestroy(); 
    } 

    @Override 
    public void onStateChanged(MorphButton.MorphState changedTo, boolean isAnimating) { 
     if (changedTo == MorphButton.MorphState.END) { 
      textToSpeech.stop(); 
     } else { 
      speakOut(); 

     } 
    } 

    private void speakOut() { 
     HashMap<String, String> params = new HashMap<String, String>(); 
     params.put(TextToSpeech.Engine.KEY_PARAM_UTTERANCE_ID, "id"); 
     textToSpeech.setPitch((float) ttSsettings.getPitchRate()); 
     textToSpeech.setSpeechRate((float) ttSsettings.getSpeechRate()); 
     textToSpeech.speak(pr[1], TextToSpeech.QUEUE_FLUSH, params); 
     } 


    //getters 
    public String getData() { 
     return data; 
    } 

    public static TextToSpeech getTextToSpeech() { 
     return textToSpeech; 
    } 
} 

Answer 1

的setOnUtteranceProgressListener()方法speak()调用之前必须被调用。现在，您首先调用您的speakOut()方法，然后才设置侦听器。它需要是相反的：

textToSpeech = new TextToSpeech(this, new TextToSpeech.OnInitListener() { 
    @Override 
    public void onInit(int i) { 
     if (i == TextToSpeech.SUCCESS) { 
      //set language Locale to US 
      int result = textToSpeech.setLanguage(loc); 
      //check that is language locale available on device or supported 
      if (result == TextToSpeech.LANG_MISSING_DATA 
        || result == TextToSpeech.LANG_NOT_SUPPORTED) { 
       Toast.makeText(guide.this, "Leanguage not present", Toast.LENGTH_SHORT).show(); 
      } else { 
       textToSpeech.setOnUtteranceProgressListener(
        new UtteranceProgressListener() { 
        @Override 
        public void onStart(String s) { 
         //if ("id".equals(s) 
         Toast.makeText(guide.this, "onStart works", Toast.LENGTH_SHORT).show(); 
        } 

        @Override 
        public void onDone(String s) { 
         //if ("id".equals(s)) 
         Toast.makeText(guide.this, "onDone works", Toast.LENGTH_SHORT).show(); 
        } 

        @Override 
        public void onError(String s) { 
         //if ("id".equals(s)) 
         Toast.makeText(guide.this, "OnError works", Toast.LENGTH_SHORT).show(); 
        } 
       });        

       speakOut(); 
      } 
     } else { 
      //show toast if initialization failed 
      Toast.makeText(getBaseContext(), "TTS Engine Initilization Failed!", Toast.LENGTH_SHORT).show(); 
     } 
    } 
});