如何从Firebase数据库读取用户信息并在Android App中显示为列表

Question

I am new here and I'd be glad if anyone can help me.What I want to do is get UID and Username of all the users and display it in a list.

Here is my related code:

mDatabase = FirebaseDatabase.getInstance().getReference();
        listView = (ListView) v.findViewById(R.id.listview);

        mDatabase.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {


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

                    **// Not sure what to do here**

                    array.add(username);
                   }

              ArrayAdapter adapter = new ArrayAdapter(getContext(), android.R.layout.simple_list_item_1, array);
              listView.setAdapter(adapter);
               }

My Users Class which I use to Insert User Information

public class User {

    public String username;
    public String phone;

    public User() {
        // Default constructor required for calls to DataSnapshot.getValue(User.class)
    }

    public User(String username, String phone) {
        this.username = username;
        this.phone = phone;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getPhone() {
        return phone;
    }


}

And this is how my Database Looks like Firebase Database

Answer 1

Please use this code:

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference usersRef = rootRef.child("users");
ValueEventListener eventListener = new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for(DataSnapshot ds : dataSnapshot.getChildren()) {
            String phone = ds.child("phone").getVelue(String.class);
            String username = ds.child("username").getValue(String.class);
            Log.d("TAG", phone + " / " + username);
        }
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {}
};
usersRef.addListenerForSingleValueEvent(eventListener);

And your uotput will be:

uo / pol
809151699 / shivam
//and so on

Hope it helps.