Android Studio中的TextToSpeech未被调用/无法正常工作

Question

下面这个简单的代码可以调用另一个视图组，这些都来自基本的第一个应用程序教程。

https://developer.android.com/training/basics/firstapp/starting-activity.html

我用这个问题为导向，以获得TTS，以及应用程序运行吐司和看法，但跳过了文本到语音： Text to speech(TTS)-Android

然后我尝试添加TTS通话/ class。我对Android很陌生，所以想知道是否有人能向我解释，或者指出我如何使用这些类并围绕它们构建帮助我理解总体的正确方向，但总体而言，解决这个问题的方法会很棒， 非常感谢！

package com.example.ollie.myapplication3;

import android.content.Context; 
    import android.content.Intent; 
    import android.net.Uri; 
    import android.os.Build; 
    import android.speech.tts.TextToSpeech; 
    import android.support.annotation.RequiresApi; 
    import android.support.v7.app.AppCompatActivity; 
    import android.os.Bundle; 
    import android.view.View; 
    import android.widget.EditText; 
    import android.widget.Toast; 

    import com.google.android.gms.appindexing.Action; 
    import com.google.android.gms.appindexing.AppIndex; 
    import com.google.android.gms.appindexing.Thing; 
    import com.google.android.gms.common.api.GoogleApiClient; 

    import java.util.Locale; 

    public class MainActivity extends AppCompatActivity implements TextToSpeech.OnInitListener { 

     public static final String EXTRA_MESSAGE = "com.example.myapplication.MESSAGE"; 
     /** 
     * ATTENTION: This was auto-generated to implement the App Indexing API. 
     * See https://g.co/AppIndexing/AndroidStudio for more information. 
     */ 
     private GoogleApiClient client; 

     @Override 
     protected void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.activity_main); 
      // ATTENTION: This was auto-generated to implement the App Indexing API. 
      // See https://g.co/AppIndexing/AndroidStudio for more information. 
      client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build(); 
     } 

     /** 
     * Called when user clicks send button 
     */ 
     public void sendMessage(View view) { 

      TextToSpeech tts = new TextToSpeech(this, this); 
      tts.setLanguage(Locale.US); 
      tts.speak("Text to say aloud", TextToSpeech.QUEUE_ADD, null, null); 

      Context context = getApplicationContext(); 
      CharSequence text = "Hello toast!"; 
      int duration = Toast.LENGTH_LONG; 

      Toast toast = Toast.makeText(context, text, duration); 
      toast.show(); 

      Intent intent = new Intent(this, DisplayMessageActivity.class); 
      EditText editText = (EditText) findViewById(R.id.edit_message); 
      String message = editText.getText().toString(); 
      intent.putExtra(EXTRA_MESSAGE, message); 
      startActivity(intent); 
     } 

     @Override 
     public void onInit(int status) { 
      TextToSpeech tts = new TextToSpeech(this, this); 
      tts.setLanguage(Locale.US); 
      tts.speak("Text to say aloud", TextToSpeech.QUEUE_ADD, null, null); 
     } 
    } 

Answer 1

尽量让你的“TTS”变量当地一个（在活动），所以你要确保你正在使用你的实例，而不是创建你按下按钮一个新的每次相同的实例。

像这样：

public class MainActivity extends AppCompatActivity { 

private TextToSpeech tts; 


@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    tts = new TextToSpeech(getApplicationContext(), new TextToSpeech.OnInitListener() { 
     @Override 
     public void onInit(int status) { 
      if(status != TextToSpeech.ERROR) { 
       tts.setLanguage(Locale.US); 
      } 
     } 
    }); 

} 


public void sendMessage(View view) { 
    tts.speak("Text to say aloud", TextToSpeech.QUEUE_ADD, null, null); 

    ... 
} 

}