在 android 的服务中,每天在特定时间安排一次 TimerTask

Schedule a TimerTask at specific time once per day in a service in android

我有一个 TimerTask 对象 timerTask。我的代码是 运行ning,但是当服务最初启动时,我的计时器任务 运行 会在指定时间之前立即执行,即 3:30 下午,尽管我希望它在 运行 3:30每天PM一次。

Calendar cal = Calendar.getInstance();
cal.set(Calendar.AM_PM, Calendar.PM);
cal.set(Calendar.HOUR, 3);    
cal.set(Calendar.MINUTE, 30);
cal.set(Calendar.SECOND, 0);
Date date = cal.getTime();
timer.schedule(timerTask, date, 1000*60*60*24); // once per day

正如其他社区用户所建议的那样,不要使用 Timertask,android AlarmManager

你可以使用。

怎么做?

  1. 用广播接收器注册警报管理器,覆盖onReceive方法(警报被触发时做什么)
  2. 设置每天的间隔时间和执行时间的闹钟。

这里有一个片段作为示例:

public class MainActivity extends Activity {
private static final String TAG ="MainActivity";
PendingIntent myPendingIntent;
AlarmManager alarmManager;
BroadcastReceiver myBroadcastReceiver;
Calendar firingCal;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //Register AlarmManager Broadcast receive.
    firingCal= Calendar.getInstance();
    firingCal.set(Calendar.HOUR, 8); // At the hour you want to fire the alarm
    firingCal.set(Calendar.MINUTE, 0); // alarm minute 
    firingCal.set(Calendar.SECOND, 0); // and alarm second
    long intendedTime = firingCal.getTimeInMillis();
    
    registerMyAlarmBroadcast();
    alarmManager.set( AlarmManager.RTC_WAKEUP, intendedTime , AlarmManager.INTERVAL_DAY , myPendingIntent );
}
 
private void registerMyAlarmBroadcast()
{
      Log.i(TAG, "Going to register Intent.RegisterAlramBroadcast");

    //This is the call back function(BroadcastReceiver) which will be call when your 
    //alarm time will reached.
    myBroadcastReceiver = new BroadcastReceiver()
    {
        @Override
        public void onReceive(Context context, Intent intent)
        {
            Log.i(TAG,"BroadcastReceiver::OnReceive()");
            Toast.makeText(context, "Your Alarm is there", Toast.LENGTH_LONG).show();
        }
    };

    registerReceiver(myBroadcastReceiver, new IntentFilter("com.alarm.example") );
    myPendingIntent = PendingIntent.getBroadcast( this, 0, new Intent("com.alarm.example"),0 );
    alarmManager = (AlarmManager)(this.getSystemService( Context.ALARM_SERVICE ));
}
private void UnregisterAlarmBroadcast()
{
    alarmManager.cancel(myPendingIntent); 
    getBaseContext().unregisterReceiver(myBroadcastReceiver);
}

@Override
protected void onDestroy() {
    unregisterReceiver(myBroadcastReceiver);
    super.onDestroy();
}
}

编辑:

如果时间可以根据用户输入在应用程序中动态更改,则只需更改 Calender firingCal 变量即可调整时间。