后台执行的定时任务

package com.pingyijinren.test;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity{
    private Button startIntentService;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Intent it=new Intent(this,LongRunningService.class);
        startService(it);
    }
}

package com.pingyijinren.test;

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.SystemClock;
import android.util.Log;

public class LongRunningService extends Service {
    public LongRunningService() {
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        throw new UnsupportedOperationException("Not yet implemented");
    }

    @Override
    public int onStartCommand(Intent intent,int flags,int startId){
        new Thread(new Runnable() {
            @Override
            public void run() {
                Log.d("MainActivity","我是子线程");
            }
        }).start();

        AlarmManager alarmManager=(AlarmManager)getSystemService(ALARM_SERVICE);
        long triggerAtTime= SystemClock.elapsedRealtime()+10*1000;
        Intent it=new Intent(this,AlarmReceiver.class);
        PendingIntent pi=PendingIntent.getBroadcast(this,0,it,0);
        alarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP,triggerAtTime,pi);
        return super.onStartCommand(intent,flags,startId);
    }
}

package com.pingyijinren.test;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class AlarmReceiver extends BroadcastReceiver {
    public AlarmReceiver() {
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO: This method is called when the BroadcastReceiver is receiving
        // an Intent broadcast.
        //throw new UnsupportedOperationException("Not yet implemented");
        Intent it=new Intent(context,LongRunningService.class);
        context.startService(it);
    }
}