How to run some task at specified time interval in android using AlarmManager?

问题

Hello stackoverflow I'm trying to develop an android application that can run some task at specific time interval, I'm using AlarmManager to do the task, the code snippet is as follows,

if (radioBtnChecked)
{   
     MyActivity.this.alarmMgr = (AlarmManager) MyActivity.this.getSystemService(Context.ALARM_SERVICE);
     Intent serviceIntent = new Intent(MyActivity.this, MyService.class);
     MyActivity.this.pi = PendingIntent.getService(MyActivity.this, 0, serviceIntent, 0);
     MyActivity.this.alarmMgr.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime(), 10000, pi);

 }//End of if condition

and MyService.java

public class MyService extends Service 
{
    @Override
    public IBinder onBind(Intent intent) 
    {
        return null;
    }//End of onBind method

    public void onStart(Intent intent, int startId) 
    {
        super.onStart(intent, startId);
        Toast.makeText(getApplicationContext(),"Service started", Toast.LENGTH_SHORT).show();
    }
}

Problem is the Service started message will be displayed for the very first time when I click the radio button, but I want the Service started message to be displayed after the 10 seconds. Please someone help me to solve this problem, please share your knowledge so that I can correct my mistakes.

Thanks in advance.

回答1:

Set AlarmManager like this:

private static final int REPEAT_TIME_IN_SECONDS = 60; //repeat every 60 seconds

AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

alarmManager.setRepeating(AlarmManager.RTC, System.currentTimeMillis(),
            REPEAT_TIME_IN_SECONDS * 1000, pendingIntent);

Change AlarmManager.RTC to AlarmManager.RTC_WAKEUP if u want to wake up phone when it goes off. More about AlarmManager here

Those two parameters also means that your alarm time will be System.currentTimeMilis() which is time in UTC.

EDIT :

Your solution using AlarmManager.ELAPSED_REALTIME which measure time since device boot including sleep. It means that if you want run this code after 10 seconds and then want to repeat it and your device is running for more than that, PendingIntent will be triggered immediately because 10 seconds after boot occurs in the past.

EDIT 2 :

If u want to run code just once after 10 seconds try this:

private static final int START_AFTER_SECONDS = 10;
...
if (radioBtnChecked)
{ 
    Runnable mRunnable;
    Handler mHandler = new Handler();
    mRunnable = new Runnable() {
        @Override
        public void run() {
            Intent serviceIntent = new Intent(MyActivity.this, MyService.class);
            MyActivity.this.startService(serviceIntent);
        }
    };
    mHandler.postDelayed(mRunnable, START_AFTER_SECONDS * 1000);
}

回答2:

try with this

alarmManagera.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(),10000, YourPendingIntent);

回答3:

replace SystemClock.elapsedRealtime() with System.currentTimeMillis()

回答4:

This code Snippet may help you

 private static final long REPEAT_TIME = 30*1000;  
  AlarmManager service = (AlarmManager) context
                .getSystemService(Context.ALARM_SERVICE);
            Intent i = new Intent(context, MyStartServiceReceiver.class);
            PendingIntent pending = PendingIntent.getBroadcast(context, 0, i,
                PendingIntent.FLAG_CANCEL_CURRENT);
            Calendar cal = Calendar.getInstance();
            cal.add(Calendar.SECOND, 30);
            service.setInexactRepeating(AlarmManager.RTC_WAKEUP,cal.getTimeInMillis(), REPEAT_TIME, pending);

In MyService class use onStartCommand(Intent intent, int flags, int startId). you have used onStart(Intent intent, int startId) which will execute once.

public class MyService extends Service 
{
    @Override
    public IBinder onBind(Intent intent) 
    {
        return null;
    }//End of onBind method

    public void onStart(Intent intent, int startId) 
    {
        super.onStart(intent, startId);
        Toast.makeText(getApplicationContext(),"Service started", Toast.LENGTH_SHORT).show();
    }

@Override
    public int onStartCommand(Intent intent, int flags, int startId)
    {
         Toast.makeText(getApplicationContext(),"onStartCommand=Service started", Toast.LENGTH_SHORT).show();        
        return Service.START_STICKY;
    }
}

来源：https://stackoverflow.com/questions/19020853/how-to-run-some-task-at-specified-time-interval-in-android-using-alarmmanager

标签

android

alarmmanager