文本到语音 - 不在后台工作

Question

我在我的Android应用中实现了一个非常基本的TTS，当应用在前台运行时似乎工作正常，但在后台运行时不起作用。它会等到应用程序返回到前台并播放队列中的内容。我的GPS追踪应用程序如何在显示屏关闭时提供跟踪反馈，从而实现这一目标？ 我的主要类实现： TextToSpeech.OnInitListener

我排队TTS有：

ttsProgressStr = "Time " + 
       timeStringForVoice(trackingTimeMillis); 
ttsEngine.speak(ttsProgressStr, TextToSpeech.QUEUE_FLUSH, null, null); 

Answer 1

请参阅本

import android.app.Activity; 
import android.os.Bundle; 
import android.speech.tts.TextToSpeech; 
import android.util.Log; 
import android.view.View; 
import android.widget.Button; 
import android.widget.EditText; 
import java.util.Locale; 

public class MainActivity extends Activity implements 
    TextToSpeech.OnInitListener { 
/** Called when the activity is first created. */ 

private TextToSpeech tts; 
private Button buttonSpeak; 
private EditText editText; 

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

    tts = new TextToSpeech(this, this); 
    buttonSpeak = (Button) findViewById(R.id.button1); 
    editText = (EditText) findViewById(R.id.editText1); 

    buttonSpeak.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View arg0) { 
      speakOut(); 
     } 

    }); 
} 

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

@Override 
public void onInit(int status) { 

    if (status == TextToSpeech.SUCCESS) { 

     int result = tts.setLanguage(Locale.US); 

     if (result == TextToSpeech.LANG_MISSING_DATA 
       || result == TextToSpeech.LANG_NOT_SUPPORTED) { 
      Log.e("TTS", "This Language is not supported"); 
     } else { 
      buttonSpeak.setEnabled(true); 
      speakOut(); 
     } 

    } else { 
     Log.e("TTS", "Initilization Failed!"); 
    } 

} 

private void speakOut() { 
    String text = editText.getText().toString(); 
    tts.speak(text, TextToSpeech.QUEUE_FLUSH, null); 
} 
} 

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:tools="http://schemas.android.com/tools" 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    tools:context=".MainActivity"> 

<EditText 
    android:id="@+id/editText1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentLeft="true" 
    android:layout_alignParentTop="true" 
    android:layout_marginLeft="77dp" 
    android:layout_marginTop="42dp" 
    android:ems="10" > 

    <requestFocus /> 
</EditText> 

<Button 
    android:id="@+id/button1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignLeft="@+id/editText1" 
    android:layout_below="@+id/editText1" 
    android:layout_marginLeft="59dp" 
    android:layout_marginTop="39dp" 
    android:text="Speak" /> 

<TextView 
    android:id="@+id/textView1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignBaseline="@+id/editText1" 
    android:layout_alignBottom="@+id/editText1" 
    android:layout_alignParentLeft="true" 
    android:text="Enter Text:" /> 

</RelativeLayout>