如何将实时 Firebase 数据库中的数据提取到数组中？

Question

我创建了一个自定义日历，它使用从 github 链接https://github.com/DeveloperBrothers/Custom-Calendar-View获取的数组“HomeCollection” ，以便在我的 android 应用程序中创建自定义日历。目前，事件数据被硬编码到这个数组中（参见下面的代码片段），但希望从我的 firebase 数据库中获取事件属性，而不是在我创建数据库并保存此类事件数据的地方（参见下面的图片链接）。HomeCollection.date_collection_arr = new ArrayList<HomeCollection>();        HomeCollection.date_collection_arr.add(new HomeCollection("2018-11-21", "Winter Table Quiz", "7-10 pm, Clubhouse", "ClubHouse", "Come along to the Winter Table Quiz, €5pp, tables of 4, theres lots of great prizes to be won."));       HomeCollection.date_collection_arr.add(new HomeCollection("2018-11-03", "u21 Division 1 Training ", "10-11am, Club Grounds", "ClubHouse", "Weekly Division 1 training. Weather dependant."));        HomeCollection.date_collection_arr.add(new HomeCollection("2018-11-03", "u21 Division 2 Training ", "11-12am, Club Grounds", "ClubHouse", "Weekly Division 2 training. Weather dependant."));        HomeCollection.date_collection_arr.add(new HomeCollection("2018-11-10", "u21 Division 1 Training ", "10-11am, Club Grounds", "ClubHouse", "Weekly Division 1 training. Weather dependant."));        HomeCollection.date_collection_arr.add(new HomeCollection("2018-11-10", "u21 Division 2 Training ", "11-12am, Club Grounds", "ClubHouse", "Weekly Division 2 training. Weather dependant."));谁能帮我将此静态代码更改为我的 Firebase 数据库数据？

Answer 1

1）你必须在你的代码中获取firebase数据引用

DatabaseReference mFireBaseDatabaseReference = FirebaseDatabase.getInstance().getReference();

2）然后你添加了firebase监听器来获取数据：

mFireBaseDatabaseReference.child("events").addListenerForSingleValueEvent(new ValueEventListener() {

            @Override

            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                //you can parse the data in your models here like this

for (DataSnapshot childSnapshot: dataSnapshot.getChildren()) {

Event event = childSnapshot.getValue(Event.class);

HomeCollection.date_collection_arr.add(event);

}

            }

            @Override

            public void onCancelled(@NonNull DatabaseError databaseError) {

            }

        });

Answer 2

因此，您可以制作一个 Java bean 来保存所有这些数据。您作为对象存储的所有数据的制作getter和方法。setter例如，为对象属性创建getter和setter方法，例如：eventDate、eventDescription 等，并假设您将 bean 命名为EventBean.java.

现在使用childEventListener这样的：

mDatabaseReference = mFirebaseDatabase.getReference().getChild("event");

mDatabaseReference.addChildEventListener(new OnChildEventListener(){

@Override

public void onChildAdded(DataSnapshot snapshot, String previousChildName){

EventBean data = snapshot.getValue(EventBean.class);//now you have got data in the 

eventbean instance

System.out.println(data.getEventDate());

}

});

我希望这就是你要找的。