Question

我想显示（用户：....），但我不知道用户的路径。如何在列表视图中选择用户显示。请查看我的代码并帮助我

public class ListUserRoom extends AppCompatActivity {

    private ListView listView;

    List<Member> members = new ArrayList<>();

    private DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference();

    private String keyOfRoom = "";

    private String keyOfMember = "";

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

        createListUser();

    }

    private void createListUser() {

        listView = (ListView)findViewById(R.id.listView);
        listView.setAdapter(new ListUserRoom.ImageAdapter(this));

        Intent getData = getIntent();
        if(getData != null){
            keyOfRoom = getData.getExtras().getString("key" , "");
        }
        getData = getIntent();
        if(getData != null){
            keyOfMember = getData.getExtras().getString("keymember" , "");
        }
        mDatabase = FirebaseDatabase.getInstance().getReference()
                .child("AllRoom").child(keyOfRoom)
                .child("Member").child(keyOfMember)
                .child("User");

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

                Set<String> set = new HashSet<String>();
                Iterator i = dataSnapshot.getChildren().iterator();
                dataSnapshot.getValue();


                while (i.hasNext()){
                    DataSnapshot data = (DataSnapshot)i.next();
                    Member member = data.getValue(Member.class);
                    member.setKey(data.getKey());
                    members.add(member);
                }
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });
    }

如何选择表用户:(全部）和Member.class为show listuser（私有字符串键，用户）设置模型，获取密钥用户

Answer 1

您在AllRoom表

之后缺少数据库引用中的子键

mDatabase = FirebaseDatabase.getInstance().getReference() 
            .child("AllRoom")
            .child(missingKey)//You need to add a key here to be able to access Member
            .child("Member");

解决之后，这里有一个我已经适应你的问题的代码

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

            for (DataSnapshot snapshot : dataSnapshot.getChildren()){
                Member member = data.getValue(Member.class);
                member.setKey(data.getKey());
                Members.add(member);
            }

        }

希望这有帮助

Firebase显示数据

1 个答案: