android 定时启动\取消

        Intent intent = new Intent("cn.pocketdigi.update.alarm");
        intent.setClass(this, AlarmReceiver.class);
 
        PendingIntent pi=PendingIntent.getBroadcast(this, 0, intent,0);
        //设置一个PendingIntent对象，发送广播
        AlarmManager am=(AlarmManager)getSystemService(ALARM_SERVICE);
        //获取AlarmManager对象
       // am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()+3500, pi);//只执行一次

        
        am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()+3500, 10000, pi); //重复执行

       <receiver android:name=".AlarmReceiver">
             <intent-filter>
                <action android:name="cn.pocketdigi.update.alarm" />
            </intent-filter>
        </receiver>

public class AlarmReceiver extends BroadcastReceiver {
	private static final String TAG = "AlarmReceiver";
	@Override
	public void onReceive(Context context, Intent intent) {
		// TODO Auto-generated method stub
		Log.v(TAG, "收到广播");
//		Intent it=new Intent(context,AlarmActivity.class);
//		it.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
//		context.startActivity(it);
		//收到广播后启动Activity,简单起见，直接就跳到了设置alarm的Activity
                         //intent必须加上Intent.FLAG_ACTIVITY_NEW_TASK flag
	}
} 

取消方式：

        Intent intent = new Intent("cn.pocketdigi.update.alarm");
        intent.setClass(this, AlarmReceiver.class);
 
        PendingIntent pi=PendingIntent.getBroadcast(this, 0, intent,0);
        AlarmManager alarm=(AlarmManager)getSystemService(ALARM_SERVICE);
        alarm.cancel(pi);

另外一种intent方式

代码 
    Intent intent =new Intent(Main.this, alarmreceiver.class);
    intent.setAction("repeating");
    PendingIntent sender=PendingIntent
        .getBroadcast(Main.this, 0, intent, 0);
        //开始时间
    long firstime=SystemClock.elapsedRealtime();

    AlarmManager am=(AlarmManager)getSystemService(ALARM_SERVICE);　　//5秒一个周期，不停的发送广播
    am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP
            , firstime, 5*1000, sender);