为什么我仅在打开活动时收到通知? [英] Why I get the Notification just opening the Activity?

问题描述

有人在STACKOVERFLOW上对此有解决方案吗?

Edit : DO anyone have a solution for this on STACKOVERFLOW ?

我正在使用Firebase数据库，并希望在添加新子项后立即显示通知.

I am using Firebase Database and wanted to show notification as soon as new child is added.

我正在使用"ChildEventListener"来获取它.

I am using "ChildEventListener" to acquire it.

这是我的代码:

 dbProducts.addChildEventListener(new ChildEventListener() {
                @Override
                public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {

//                    Toast.makeText(ShowNotifActivity.this, "Child Added ", Toast.LENGTH_SHORT).show();

                    Intent intent = new Intent(ShowNotifActivity.this, MainActivity.class);
                    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(), 0, intent, PendingIntent.FLAG_ONE_SHOT);
                    String channelId = "MyNotifications";
                    NotificationCompat.Builder builder = new NotificationCompat.Builder(getApplicationContext(), channelId)
                            .setSmallIcon(R.drawable.notification)
                            // .setLargeIcon(R.drawable.ic_notifications_active_black_24dp)

                            .setContentTitle("New Notification")
                            .setContentText("Click here to View ");
                    ;
                    NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                        NotificationChannel channel = new NotificationChannel(channelId, "MyNotifications", NotificationManager.IMPORTANCE_DEFAULT);
                        manager.createNotificationChannel(channel);
                    }
                    manager.notify(0, builder.build());

                }

                @Override
                public void onChildChanged(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
//                    Toast.makeText(ShowNotifActivity.this, "Child Changed", Toast.LENGTH_SHORT).show();
                }

                @Override
                public void onChildRemoved(@NonNull DataSnapshot dataSnapshot) {

                }

                @Override
                public void onChildMoved(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {

                }

                @Override
                public void onCancelled(@NonNull DatabaseError databaseError) {

                }
            });

在Firebase数据库中添加新子项后，如何仅显示一次通知.

How can the Notification be shown only once as a new child is added in firebase database.

问题是，一旦我打开Activity，通知就会触发，即使我没有更新它也没有更改或添加数据库中的任何内容.怎么解决

the problem is as soon as i open the Activity , the notification triggers even when i have not updated it changed or added anything in the database. How can it be fixed

推荐答案

当您使用addChildEventListener在数据库中的某个位置附加一个侦听器时，即使该位置上的每个孩子都被调用一次onChildAdded，即使这不是新的.这就是为什么您的通知始终显示的原因.

When you use addChildEventListener to attach a listener at a location in the database, onChildAdded will get called once for each child at that location, even if it isn't new. That's why your notification is always showing.

如果您只想获取新"项目，则需要想出一种方法来确定用户实际上是哪些新孩子，并为查询中的那些孩子进行过滤.也许时间戳或其他标记会为您工作.

If you only want to get "new" items, you will need to come up with a way to determine which children are actually new to the user, and filter for those children in your query. Maybe a timestamp or some other flag will work for you.

这篇关于为什么我仅在打开活动时收到通知?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！