Android 在回收站视图中创建多个通知

Question

I'm creating an app which tracks when a food item expires and in the adapter class I have an if statement and when the item expiry date is less than 24 hours it displays a notification but when I have more than one item which is about to expire in my recycler view, it only shows the one notification I want it to show each item that is about to expire in separate notifications.

if (timeLeft > 86400000) {
   viewHolder.item_expire_date.setBackgroundColor(Color.parseColor("#3deb34"));
   viewHolder.item_expire_date.setText(days + " Days \n" + hours + " Hours\n" + minutes + " Minutes\n" + seconds + " Seconds"); 
 } else if (timeLeft > 0 && timeLeft <= 86400000) {
   int reqCode = 1;
   showNotification(context, items.getNAME()+ " Urgent expiry date", items.getNAME()+" is about to expire in less than 24 hours", reqCode);
   viewHolder.item_expire_date.setBackgroundColor(Color.parseColor("#f55742"));
   viewHolder.item_expire_date.setText(days + " Days \n" + hours + " Hours\n" + minutes + " Minutes\n" + seconds + " Seconds");
 } else {
   viewHolder.item_expire_date.setBackgroundColor(Color.parseColor("#000000"));
   viewHolder.item_expire_date.setText("\"Re-enter Date\"");
 }                     

Creating Notification

public void showNotification(Context context, String title, String message, int reqCode) {

        String CHANNEL_ID = "channel_name";// 
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(context, CHANNEL_ID)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle(title)
                .setContentText(message)
                .setAutoCancel(true);
        NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            CharSequence name = "Channel Name";// The user-visible name of the channel.
            int importance = NotificationManager.IMPORTANCE_HIGH;
            NotificationChannel mChannel = new NotificationChannel(CHANNEL_ID, name, importance);
            notificationManager.createNotificationChannel(mChannel);
        }
        notificationManager.notify(reqCode, notificationBuilder.build()); 
    }

Answer 1

The reqCode that you're using for each notification needs to be unique. A simple solution would be using your timeLeft , assuming that is unique for each food item.

This can be verified by looking at the comment above the .notify method, specifically:

If a notification with the same id has already been posted by your application and has not yet been canceled, it will be replaced by the updated information.

Source code:

/**
 * Post a notification to be shown in the status bar. If a notification with
 * the same id has already been posted by your application and has not yet been canceled, it
 * will be replaced by the updated information.
 *
 * @param id An identifier for this notification unique within your
 *        application.
 * @param notification A {@link Notification} object describing what to show the user. Must not
 *        be null.
 */
public void notify(int id, Notification notification)
{
    notify(null, id, notification);
}