Android的文本到语音的NullPointerException

Question

下面是我有：

ImageView iv, in, out; 
Button back, home, talk; 
TextView header, desc; 
private TextToSpeech tts; 

    private void initControls(){ 

    iv = (ImageView) findViewById (R.id.ivExercise); 
    back = (Button) findViewById (R.id.tabs_back); 
    home = (Button) findViewById (R.id.tabs_home); 
    back.setOnClickListener(this); 
    home.setOnClickListener(this); 
    header = (TextView) findViewById (R.id.txtMenuHeader); 
    header.setText(R.string.bicycling); 

    talk = (Button) findViewById (R.id.btnTalk); 

    desc = (TextView) findViewById (R.id.notedesc); 
    desc.setText(R.string.bicyclingnote); 
    iv.setImageResource(R.drawable.bicycling); 

    out = (ImageView) findViewById (R.id.ibZoomOut); 
    in = (ImageView) findViewById (R.id.ibZoomIn); 
    out.setOnClickListener(this); 
    in.setOnClickListener(this); 
    talk.setOnClickListener(this); 


} 

public void onClick(View v) { 
    // TODO Auto-generated method stub 
    switch(v.getId()){ 
    case R.id.tabs_back: 
     finish(); 
     break; 
    case R.id.tabs_home: 
      Intent home = new Intent(Bicycling.this, IHealthFirstActivity.class); 
      home.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
      startActivity(home); 
      break; 
    case R.id.ibZoomIn: 
     desc.setTextSize(TypedValue.COMPLEX_UNIT_PX,(desc.getTextSize()+1f)); 
     break; 
    case R.id.ibZoomOut: 
     desc.setTextSize(TypedValue.COMPLEX_UNIT_PX,(desc.getTextSize()-1f)); 
     break; 
    case R.id.btnTalk: 
     speakOut(); 
     break; 
    } 
} 

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

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"); 
      Toast.makeText(getBaseContext(), "This language is not supported", Toast.LENGTH_SHORT).show(); 
     } else { 
      talk.setEnabled(true); 
      speakOut(); 
     } 

    } else { 
     // Log.e("TTS", "Initilization Failed!"); 
     Toast.makeText(getBaseContext(), "Initialization Failed!", Toast.LENGTH_SHORT).show(); 
    } 

} 

private void speakOut() { 
    // TODO Auto-generated method stub 
    String text = "I'm Android!"; //desc.getText().toString(); 
    tts.speak(text, TextToSpeech.QUEUE_FLUSH, null); 
} 

我在这一行一个NullPointerException：

tts.speak(text, TextToSpeech.QUEUE_FLUSH, null); 

我跟经过这里的教程http://www.androidhive.info/2012/01/android-text-to-speech-tutorial/ 我想有什么东西我失踪。请帮忙。谢谢。

Answer 1

你忘了初始化tts作为

tts = new TextToSpeech(this, this);