为什么if语句在仿真器上工作，但不在实际设备上工作

Question

我想要有一个定时器对话框，它将从0开始，每5秒发出一个声音。它适用于Nexus S API 22的仿真器，但不适用于我的HTC One M8 API 21手机。记录日志消息并在模拟器上听到声音，但在我的实际电话上都没有发生，所以我认为这不是一个合理的问题。

private Runnable updateTimerThread = new Runnable() { 

    public void run() { 
     timeInMilliseconds = SystemClock.uptimeMillis() - startTime; 

     updatedTime = timeSwapBuff + timeInMilliseconds; 

     int secs = (int) (updatedTime/1000); 
     int mins = secs/60; 
     secs = secs % 60; 
     int milliseconds = (int) (updatedTime % 1000); 

     if(secs > 0 && ((secs%5) == 0) && milliseconds == 0){ 
      Log.d("BEEP", "beep"); 
      tg.startTone(ToneGenerator.TONE_PROP_BEEP); 
     } 

     timerValue.setText("" + mins + ":" 
       + String.format("%02d", secs) + ":" 
       + String.format("%03d", milliseconds)); 
     customHandler.postDelayed(this, 0); 
    } 
}; 

这里也是用于参考的onCreate和变量名。

public class TimerDialogFragment extends DialogFragment implements DialogInterface.OnClickListener{  

private TextView timerValue; 

private long startTime = 0L; 

private Handler customHandler = new Handler(); 

long timeInMilliseconds = 0L; 
long timeSwapBuff = 0L; 
long updatedTime = 0L; 

ToneGenerator tg; 

@Override 
public Dialog onCreateDialog(Bundle savedInstanceState) { 
    super.onCreateDialog(savedInstanceState); 
    View v = getActivity().getLayoutInflater().inflate(R.layout.dialog_timer,null); 

    tg = new ToneGenerator(AudioManager.STREAM_NOTIFICATION, 100); 

    timerValue = (TextView) v.findViewById(R.id.timerText); 
    startTime = SystemClock.uptimeMillis(); 
    customHandler.postDelayed(updateTimerThread, 0); 



    return new AlertDialog.Builder(getActivity()) 
      .setView(v) 
      .setMessage("") 
      .setCancelable(true) 
      .setNegativeButton("Continue with instructions",this) 
      .create(); 
} 

.... 

} 

Answer 1

在这个片断：

if(secs > 0 && ((secs%5) == 0) && milliseconds == 0){ 
     Log.d("BEEP", "beep"); 
     tg.startTone(ToneGenerator.TONE_PROP_BEEP); 
    } 

你在milliseconds计数是为了为0的蜂鸣声。这不是一个可靠的假设 - 这是一种非常糟糕的编码习惯。如果你想发出蜂鸣声，每5秒，改变你的Runnable这样：

private Runnable updateTimerThread = new Runnable() { 
    public void run() { 
    timeInMilliseconds = SystemClock.uptimeMillis() - startTime; 

    updatedTime = timeSwapBuff + timeInMilliseconds; 

    int secs = (int) (updatedTime/1000); 
    int mins = secs/60; 
    secs = secs % 60; 
    int milliseconds = (int) (updatedTime % 1000); 

    // if(secs > 0 && ((secs%5) == 0) && milliseconds == 0){ // <<<<<<<<< 
    Log.d("BEEP", "beep"); 
    tg.startTone(ToneGenerator.TONE_PROP_BEEP); 
    // } // <<<<<<<<< 

    timerValue.setText("" + mins + ":" 
      + String.format("%02d", secs) + ":" 
      + String.format("%03d", milliseconds)); 
    customHandler.postDelayed(this, 5000); // <<<<<<<<< 
    } 
};