Question

我正在使用计时器来调用WebService，它将每隔5秒轮询我的代码

timer=new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
        @Override
        public void run() {
            // TODO Auto-generated method stub
            new MyWS().execute(URL);    
        }
    }, 1000, 5000);

但它在MyWS（）上给了我FATAL异常.execute（URL）;线。以下显示log cat

05-30 11:46:47.299: E/AndroidRuntime(2801): FATAL EXCEPTION: Timer-0
05-30 11:46:47.299: E/AndroidRuntime(2801): java.lang.ExceptionInInitializerError
05-30 11:46:47.299: E/AndroidRuntime(2801):     at com.example.vuzixvideo.MainActivity$1.run(MainActivity.java:59)
05-30 11:46:47.299: E/AndroidRuntime(2801):     at java.util.Timer$TimerImpl.run(Timer.java:284)
05-30 11:46:47.299: E/AndroidRuntime(2801): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
05-30 11:46:47.299: E/AndroidRuntime(2801):     at android.os.Handler.<init>(Handler.java:121)
05-30 11:46:47.299: E/AndroidRuntime(2801):     at android.os.AsyncTask$InternalHandler.<init>(AsyncTask.java:607)
05-30 11:46:47.299: E/AndroidRuntime(2801):     at android.os.AsyncTask$InternalHandler.<init>(AsyncTask.java:607)
05-30 11:46:47.299: E/AndroidRuntime(2801):     at android.os.AsyncTask.<clinit>(AsyncTask.java:190)

Answer 1

您在计时器中执行的操作必须尝试执行需要在主UI线程上执行的操作。试试这个：

timer=new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
    @Override
    public void run() {
       runOnUiThread(new Runnable() {
           @Override
           public void run() {
               new MyWS().execute(URL);   
           }
       });
   }
}, 1000, 5000);

或者这个：

private Timer mTimer1;
private TimerTask mTt1;
private Handler mTimerHandler = new Handler(Looper.getMainLooper());

private void stopTimer(){
    if(mTimer1 != null){
        mTimer1.cancel();
        mTimer1.purge();
    }
}

private void startTimer(){
    mTimer1 = new Timer();
    mTt1 = new TimerTask() {
        public void run() {
            mTimerHandler.post(new Runnable() {
                public void run(){
                    new MyWS().execute(URL);   
                }
            });
        }
    };

    mTimer1.schedule(mTt1, 1, 5000);
}

这会在主循环器上创建一个处理程序，计时器会向其发布操作。我没有测试它，但它应该工作。

Timer-0致命错误

1 个答案: