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我开发了自己的 Chronometer 实现。我做了以下事情：

  1. 创建一个服务 (CronoService)，它使用执行线程的 Runnable 对象。Runnable 将每 0.1 秒循环一次。

  2. 将接收来自 Ui 的消息以启动、暂停或恢复 Chronometer 的 Messenger 对象。

  3. 将在 Runnable 对象的每个循环之后广播时间的意图。

代码是：

public class CronoService extends Service {

public static final int PARAR = 0;
public static final int EMPEZAR = 1;
public static final int ESTABLECER_TIEMPO = 2;

private static final String TAG = "BroadcastService";

public static final String BROADCAST_ACTION = "jose.planilla.mostrartiempo";
final Messenger mMessenger = new Messenger(new IncomingHandler());

private final Handler handler = new Handler();
private Intent intent;
private long mDec;
private long mTotalMilis;
private long mLastMilis;
private long mElapsedTime;
private long mCurrentMilis;
private int mSeconds;
private int mMin;

private Runnable sendUpdatesToUI = new Runnable() {
    public void run() {
        mCurrentMilis = System.currentTimeMillis();
        mElapsedTime = mCurrentMilis - mLastMilis;
        mLastMilis = mCurrentMilis;
        mTotalMilis += mElapsedTime;
        DisplayLoggingInfo();
        handler.postDelayed(this, 100); // 0.1 seconds
        Log.d("run()", String.valueOf(mTotalMilis));
    }
};  



@Override
public void onCreate(){
    super.onCreate();

    intent = new Intent(BROADCAST_ACTION);

}

@Override
public void onStart(Intent intent, int startId){
    mTotalMilis = intent.getLongExtra("milis", 0);
    handler.removeCallbacks(sendUpdatesToUI);
    handler.postDelayed(sendUpdatesToUI, 100); // 0.1 second 
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    Log.d(TAG, "onStart()");
    mLastMilis = mElapsedTime = System.currentTimeMillis(); 
    mTotalMilis = intent.getLongExtra("milis", 0);
    handler.removeCallbacks(sendUpdatesToUI);
    DisplayLoggingInfo();
    //handler.postDelayed(sendUpdatesToUI, 100); // 0.1 second 

    return START_NOT_STICKY;
}    

@Override
public IBinder onBind(Intent arg0) {
    return mMessenger.getBinder();
}


private void DisplayLoggingInfo() { 
    String tiempo;

    mDec = mTotalMilis % 1000;
    mDec = mDec / 100;
    mSeconds = (int) (mTotalMilis / 1000);
    mMin = mSeconds / 60;
    mSeconds = mSeconds % 60;
    tiempo = "" + mDec;

    if(mSeconds < 10)
        tiempo = ":0" + mSeconds + "." + tiempo;
    else
        tiempo = ":" + mSeconds + "." + tiempo; 

    if(mMin < 10 )
        tiempo = "0" + mMin + tiempo;
    else
        tiempo = mMin + tiempo;

    intent.putExtra("tiempo", tiempo);
    intent.putExtra("milis", mTotalMilis);
    sendBroadcast(intent);
}

@Override
public void onDestroy() {       
    handler.removeCallbacks(sendUpdatesToUI);
    super.onDestroy();
}

public void pause(){
    handler.removeCallbacks(sendUpdatesToUI);
}

public void resume(){
    handler.postDelayed(sendUpdatesToUI, 100);
}

class IncomingHandler extends Handler {
    @Override
    public void handleMessage(Message msg){ 
        switch(msg.what) {
            case PARAR:
                pause();
                break;
            case EMPEZAR:
                resume();
                break;
            case ESTABLECER_TIEMPO: 
                mTotalMilis = (Long) msg.obj;
                break;
            default:
                super.handleMessage(msg);
        }
    }
}

我的问题是我的 Chronometer 比普通的要慢一些。它每秒钟损失一点时间。我做错了什么，但我找不到问题。非常感谢。

编辑 工作代码更新。

4

1 回答 1

1

有一种更简单的方法对我来说效果很好：玩Sistem.getCurrentMillis()

看看这个： Android：毫秒计时？

于 2011-11-14T08:27:29.910 回答