如何管理通知推送系统

Question

我必须管理该图中显示的一组通知（不要担心重复项）：

我必须为每个项目发送一个通知，管理何时删除通知（因此应用程序没有发送通知）以及“通知”的更改时间（日期和时间）。 该应用程序处于后台/睡眠状态时，如何管理所有这些内容？

这是我在CoreActivity.java中的方法：

public void notifyPush(Date datetime)
    {
        Uri soundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        //Intent intent = new Intent(context,NotificationReceiver.class);
        //PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, intent, 0);

        //nuovo codice
        Intent intent = new Intent(CoreActivity.this , NotificationReceiver.class);
        AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
        PendingIntent pendingIntent = PendingIntent.getService(CoreActivity.this, 0, intent, 0);

        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.HOUR_OF_DAY, 12);
        calendar.set(Calendar.MINUTE, 00);
        calendar.set(Calendar.SECOND, 00);

        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), 24*60*60*1000 , pendingIntent);  //set repeating every 24 hours



        //fine nuovo codice
        Notification notification = new Notification.Builder(context)
                .setSound(soundUri)
                .setContentIntent(pendingIntent)
                .setSmallIcon(R.drawable.ic_launcher_foreground)
                .setContentTitle("Notifica")
                .setContentText("Abbiamo le notifiche").
                        addAction(R.drawable.ic_launcher_foreground, "Open", pendingIntent)
                .addAction(0, "Remind", pendingIntent).build();

        NotificationManager notifManager = (NotificationManager) context.getSystemService(NOTIFICATION_SERVICE);
        notifManager.notify(0, notification);
    }

NotificationReceiver.java

package com.example.msnma.movienotifier.notify;

import android.os.Bundle;
import android.app.Activity;
import android.widget.TextView;

import com.example.msnma.movienotifier.R;

public class NotificationReceiver extends Activity {

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

        TextView tv = new TextView(this);
        tv.setText("Notification Text");

        setContentView(tv);
    }

}