My AlarmManager for service update doesn't work

问题

Why my AlarmManager for service update doesn't work? this is my code:

public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       startService();

    }
     // Method to start the service
       public void startService() {
          startService(new Intent(getBaseContext(), MyService.class));
       }

       // Method to stop the service
       public void stopService() {
          stopService(new Intent(getBaseContext(), MyService.class));
       }

Service class:

public class MyService extends Service {

    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
       public int onStartCommand(Intent intent, int flags, int startId) {
          // Let it continue running until it is stopped.
          Toast.makeText(this, "Service Started", Toast.LENGTH_LONG).show();
          return START_STICKY;
       }
    @Override
    public void onCreate() {
        poruka();
        super.onCreate();
    }
    public void poruka(){
        Toast.makeText(this, "OnCreate work!", Toast.LENGTH_LONG).show();

    }
}

BroadcastReceiver and AlarmManager:

public class ServiceBroadcast extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        context.startService(new Intent(context, MyService.class));

           Intent alarmIntent = new Intent(context, ServiceBroadcast.class);
           PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, alarmIntent, PendingIntent.FLAG_UPDATE_CURRENT);
           AlarmManager alarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);  
           alarmManager.setRepeating(AlarmManager.RTC, Calendar.getInstance().getTimeInMillis(), 30*1000, pendingIntent);

    }

} And Permissions:

<application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="me.example.nservice.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service android:name=".MyService" android:enabled="true"
            android:label="Servisv1" />
        <receiver android:name="me.example.rqservice.ServiceBroadcast" android:process=":remote">
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED" />
            </intent-filter>
        </receiver>
    </application>

I receive message "OnCreate work!" and "Service Started" only first time when i open app. Why update doesn't work every 30 sec?

回答1:

To start a service every 30 seconds :

Inside onCreate() :

Here MyService is the name of the Service.

Intent myService = new Intent(this, MyService.class);
PendingIntent pendingIntent = PendingIntent.getService(
this, 0, myService, 0);

AlarmManager alarmManager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,
System.currentTimeMillis(), 30*1000,pendingIntent);

This'll start your service every 30 seconds. However, if the service is already running, which might be the case once it has been started the first time, from next time onwards the call will directly go to onStartCommand() method of the Service and not onCreate().

This is all that you need to do. However, if you want to make sure that the AlarmManager keeps restarting the service even after a phone is restarted, you'll need to add a BroadcastReceiver for Boot.

来源：https://stackoverflow.com/questions/24324693/my-alarmmanager-for-service-update-doesnt-work