Android-Firebase将数据检索到列表视图中，但不可见

Question

我已经为数据库添加了内容，并创建了一个列表视图以检索数据并将其转换为列表视图，但是它没有出现在我的应用程序中。有人可以帮我看看我的代码出了什么问题吗？

这是我的阵列适配器

public class Foodlist extends ArrayAdapter<Food> {

private Activity context;
private List<Food> foodlists;

public Foodlist(Activity context, List<Food> foodlists){
    super(context, R.layout.list_layout, foodlists);
    this.context = context;
    this.foodlists = foodlists;
}

@NonNull
@Override
public View getView(int position,  View convertView, ViewGroup parent) {
    LayoutInflater inflater = context.getLayoutInflater();

    View listViewItem = inflater.inflate(R.layout.list_layout, null , true);

    TextView textViewName = (TextView) 
    listViewItem.findViewById(R.id.textViewName);
    TextView textViewType = (TextView) 
    listViewItem.findViewById(R.id.textViewType);

    Food food = foodlists.get(position);
    textViewName.setText(food.getFoodName());
    textViewType.setText(food.getFoodType());

    return listViewItem;


  }
}

这是我的课程文件

package com.example.asus.mobilefoodpicker;

public class Food {

private String foodid,foodname, foodtype;

public Food(){

}

public Food(String id, String name, String type) {
    this.foodid = id;
    this.foodname = name;
    this.foodtype = type;
}

public String getFoodId() {
    return foodid;
}

public String getFoodName() {
    return foodname;
}

public String getFoodType() {
    return foodtype;
}
}

将显示活动列表视图

package com.example.asus.mobilefoodpicker;

import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.view.View;
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.firebase.client.Firebase;
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 Addbreakfast extends AppCompatActivity {
private EditText EnterFN;
private Button buttonadd;
Spinner spinnerfoodtype;

DatabaseReference databasemobilefoodpicker;
ListView listViewFood;

List<Food> foodlists;



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

    databasemobilefoodpicker = 
FirebaseDatabase.getInstance().getReference("food");

    EnterFN = (EditText)findViewById(R.id.Efn);
    buttonadd = (Button) findViewById(R.id.sbtn);
    spinnerfoodtype = (Spinner) findViewById(R.id.spinner);
    foodlists = new ArrayList<>();

    listViewFood = (ListView) findViewById(R.id.listViewFood);

    buttonadd.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) {
            addfood();

        }
    });

}

@Override
protected void onStart() {
    super.onStart();
    databasemobilefoodpicker.addValueEventListener(new ValueEventListener() 
{
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {

            foodlists.clear();

            for(DataSnapshot foodSnapshot : dataSnapshot.getChildren()){
                Food food = foodSnapshot.getValue(Food.class);

                foodlists.add(food);
            }

            Foodlist adapter = new Foodlist(Addbreakfast.this, foodlists);
            listViewFood.setAdapter(adapter);
        }

        @Override
        public void onCancelled( DatabaseError databaseError) {

        }
    });
}

private void addfood(){
    String name = EnterFN.getText().toString().trim();
    String foodtype = spinnerfoodtype.getSelectedItem().toString();

    if(!TextUtils.isEmpty(name)){
        String id = databasemobilefoodpicker.push().getKey();

        Food food = new Food(id,name,foodtype);

        databasemobilefoodpicker.child(id).setValue(food);

        Toast.makeText(this,"Food Added", Toast.LENGTH_LONG).show();

    }else{
        Toast.makeText(this, "You should enter a name", 
Toast.LENGTH_LONG).show();
    }
}

}

列表视图将显示数据库中的数据，但文本不可见。