定制适配器在首次加载时不显示数据，但在第一次加载后正确显示数据

Question

我正在使用customadapter填充列表，并且这些值是从firebase实时服务器获取的。当前活动是导航抽屉活动，点击抽屉中的元素将显示包含反馈和用户名的数据列表。

我的问题-在第一次点击导航抽屉元素时，没有显示用户名，但之后每次点击都会正确显示列表（带有反馈和名称）。

这是我的Firebase数据库

package com.example.arpan.yo;

import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.util.Log;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Spinner;
import android.widget.Toast;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.ArrayList;
import java.util.List;

public class Food extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {
    public static FirebaseAuth mFirebaseAuth;
    public static FirebaseUser mFirebaseUser;
    public static DatabaseReference mDatabase;
    public static String mUserId;
    CustomAdapter adapterhr;
    final ArrayList<Data> row=new ArrayList<Data>();
    ListView listView1;
    String s;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_food);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);





    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent i=new Intent(Food.this,feedbackinf.class);
            startActivity(i);
        }
    });

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.addDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);






    // Initialize Firebase Auth
    mFirebaseAuth = FirebaseAuth.getInstance();
    mFirebaseUser = mFirebaseAuth.getCurrentUser();

    if (mFirebaseUser == null) {
        // Not logged in, launch the Log In activity
        loadLogInView();
    }
    //-----------------------------------------------------------
    // Initialize Firebase Auth and Database Reference
    mFirebaseAuth = FirebaseAuth.getInstance();
    mFirebaseUser = mFirebaseAuth.getCurrentUser();
    mDatabase = FirebaseDatabase.getInstance().getReference();

    if (mFirebaseUser == null) {
        // Not logged in, launch the Log In activity
        loadLogInView();
    } else {
        mUserId = mFirebaseUser.getUid();
    }

    listView1 = (ListView) findViewById(R.id.listView);
}

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}
private void loadLogInView() {
    Intent intent = new Intent(this, LogInActivity.class);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
    startActivity(intent);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_logout) {
        mFirebaseAuth.signOut();
        loadLogInView();
    }

    return super.onOptionsItemSelected(item);
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();
        rfeedbackpublic(mDatabase.child("Feedback").child("Food"));
        rfeedbackanonymous(mDatabase.child("Feedback").child("Food"));



    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}



public String rusername(String r1)
{
    Toast.makeText(getApplicationContext(),r1, Toast.LENGTH_SHORT).show();
    mDatabase.child("users").child(r1).child("username").addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            s=(String)dataSnapshot.getValue();
            listView1.setAdapter(adapterhr);
        }

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

        }
    });
    adapterhr.notifyDataSetChanged();
    Toast.makeText(getApplicationContext(),s, Toast.LENGTH_SHORT).show();
    return s;
}

public void rfeedbackanonymous(DatabaseReference r)
{

    adapterhr=new CustomAdapter(row,this);
    adapterhr.clear();
    listView1.setAdapter(adapterhr);
    r.child("Anonymous").addChildEventListener(new ChildEventListener() {
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String s) {
            row.add(new Data( (String) dataSnapshot.getValue() ,"Anonymous"));
            adapterhr.notifyDataSetChanged();
        }

        @Override
        public void onChildChanged(DataSnapshot dataSnapshot, String s) {

        }

        @Override
        public void onChildRemoved(DataSnapshot dataSnapshot) {

        }

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

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });
}

public void rfeedbackpublic(DatabaseReference r)
{

    r.child("Public").addChildEventListener(new ChildEventListener() {
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String s) {
            for(DataSnapshot ds : dataSnapshot.getChildren()) {
                row.add(new Data(ds.getValue(String.class),rusername(dataSnapshot.getKey())));
                listView1.setAdapter(adapterhr);
                adapterhr.notifyDataSetChanged();
            }
        }

        @Override
        public void onChildChanged(DataSnapshot dataSnapshot, String s) {

        }

        @Override
        public void onChildRemoved(DataSnapshot dataSnapshot) {

        }

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

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });
}













}

PS- rfeedback匿名函数正常运行，但rfeedbackpublic函数也无法正常运行。