如何在Android中使用Alarm Manager启动服务？

Question

在我的应用程序中,我正在尝试使用警报管理器启动服务.当我点击按钮时,服务应该在我给出的特定时间开始.我的警报管理器代码如下:

public void onClick(View view) 
{
    if(view == m_btnActivate)
    {
        Calendar cur_cal = Calendar.getInstance();
        cur_cal.setTimeInMillis(System.currentTimeMillis());
        cur_cal.add(Calendar.SECOND, 50);
        Log.d("Testing", "Calender Set time:"+cur_cal.getTime());
        Intent intent = new Intent(DashboardScreen.this, ServiceClass.class);
        Log.d("Testing", "Intent created");
        PendingIntent pi = PendingIntent.getService(DashboardScreen.this, 0, intent, 0);
        AlarmManager alarm_manager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
        alarm_manager.set(AlarmManager.RTC, cur_cal.getTimeInMillis(), pi);
        Log.d("Testing", "alarm manager set");
        Toast.makeText(this, "ServiceClass.onCreate()", Toast.LENGTH_LONG).show();
    }
}

而bellow是我的服务类:

    public class ServiceClass extends Service{

    @Override
    public void onCreate() {
        // TODO Auto-generated method stub
        super.onCreate();
        Log.d("Testing", "Service got created");
        Toast.makeText(this, "ServiceClass.onCreate()", Toast.LENGTH_LONG).show();
    }

    @Override
    public IBinder onBind(Intent arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
    }

    @Override
    public void onStart(Intent intent, int startId) {
        // TODO Auto-generated method stub
        super.onStart(intent, startId);
        Toast.makeText(this, "ServiceClass.onStart()", Toast.LENGTH_LONG).show();
        Log.d("Testing", "Service got started");
    }

}

如果服务将启动,它应该在服务类中打印日志消息.但它没有表现出来.任何人都可以帮忙吗？

Answer 1

这是我用过的,从当前时间开始服务30秒后,

Intent intent = new Intent(DashboardScreen.this, ServiceClass.class);
PendingIntent pintent = PendingIntent.getService(DashboardScreen.this, 0, intent, 0);
AlarmManager alarm = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
alarm.setRepeating(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), 30*1000, pintent);

尝试一下,让我知道发生了什么......

编辑:

在manifest.xml文件中

 <service android:enabled="true" android:name=".ServiceClass" />

Answer 2

我知道这是一个老问题,但只是为了帮助谷歌的人们,这里是你如何保持你的服务活着.

    Intent ishintent = new Intent(this, HeartBeat.class);
    PendingIntent pintent = PendingIntent.getService(this, 0, ishintent, 0);
    AlarmManager alarm = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
    alarm.cancel(pintent);
    alarm.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(),5000, pintent);

该服务每5秒钟被杀死并重新启动一次.