Question

我有一项服务，我想在后台每分钟执行一项任务。只要用户正在使用手机，它就不需要在手机处于睡眠状态时执行任务。我试图用一个IntentService来做这个，它设置如下：

public class CounterService extends IntentService{

    public CounterService() {
        super("CounterService");
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
       return super.onStartCommand(intent,flags,startId);
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        Toast.makeText(this, "onhandleintent", Toast.LENGTH_SHORT).show();
        while(true)
        {
            //one minute is 60*1000
            try {
                Thread.sleep(5 * 1000);
                Toast.makeText(getApplicationContext(), "getting app count", Toast.LENGTH_LONG).show();
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}

现在为了让功能正常工作我只想让它每5秒钟显示一次吐司，我会在一分钟之后将其更改。如果我已注释掉while(true)，则会显示“onhandleintent”消息。但是，如果我运行以下代码，则不会显示Toasts。我该如何解决这个问题？

Answer 1

这将每分钟向您的服务发送一个意图，而不会在您的活动中使用任何处理器时间

  Intent myIntent = new Intent(context, MyServiceReceiver.class);
  PendingIntent pendingIntent = PendingIntent.getBroadcast(context,  0, myIntent, 0);

  AlarmManager alarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
  Calendar calendar = Calendar.getInstance();
  calendar.setTimeInMillis(System.currentTimeMillis());
  calendar.add(Calendar.SECOND, 60); // first time
  long frequency= 60 * 1000; // in ms 
  alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), frequency, pendingIntent);

调整MyServiceReceiver.class以匹配您的目标服务或活动。 documentation提供了更多详细信息来微调您的调用，例如您是否需要精确计时，在一天中的特定时间执行...

Answer 2

您需要退出主线程以避免冒ANR的风险。

而是添加一个处理程序

Handler mHandler = new Handler();

...

@Override
protected void onHandleIntent(Intent intent) {
    Toast.makeText(this, "onhandleintent", Toast.LENGTH_SHORT).show();
    mHandler.postDelayed( ToastRunnable, 5000);
    //while(true)
    //{

        //one minute is 60*1000
        //try {
        //    Thread.sleep(5 * 1000);
        //    Toast.makeText(getApplicationContext(), "getting app count",          
        //Toast.LENGTH_LONG).show();
        //} catch (InterruptedException e) {
            // TODO Auto-generated catch block
        //    e.printStackTrace();
        //}
    //}
}
final Runnable ToastRunnable = new Runnable(){
    public void run(){
         Toast.makeText(getApplicationContext(), "getting app count",          
               Toast.LENGTH_LONG).show();
         mHandler.postDelayed( ToastRunnable, 5000);
    }
}

Answer 3

这样做

    private void ping() {
    try {
        //Your code here or call a method
    } catch (Exception e) {
        Log.e("Error", "In onStartCommand");
        e.printStackTrace();
    }
      scheduleNext();
    }

    private void scheduleNext() {
      mHandler.postDelayed(new Runnable() {
        public void run() { ping(); }
      }, 60000);
    }

    public int onStartCommand(Intent intent, int x, int y) {
      mHandler = new android.os.Handler();
      ping();
      return START_STICKY;
    }

每分钟运行一次的服务

3 个答案: