Android Firebase Listview 检索数据

Question

enter image description here 我正在使用 Firebase 数据库开发 android。我想检索 firebase 数据库列表视图上的数据。我正在提供必须检索哪些数据的代码和图片。

模型类：

public class FoodItemclass {

private String ItemName;
private String price;


private int count;

public FoodItemclass()
{}
public FoodItemclass(String itemane,String itemprice,int con)
{
    ItemName = itemane;
    price =itemprice;
    count = con;
}

public String getmItemName() {
    return ItemName;
}

public void setmItemName(String mItemName) {
    this.ItemName = mItemName;
}

public String getmItemPrice() {
    return price;
}

public void setmItemPrice(String mItemPrice) {
    this.price = mItemPrice;
}

public int getCount() {
    return count;
}

public void setCount(int count) {
    this.count = count;
}

}

适配器类：

public class FoodItemAdapter extends ArrayAdapter<FoodItemclass> {


public FoodItemAdapter(Activity context, List<FoodItemclass> arrayList)
{
    super(context,0,arrayList);
}


@Override
public View getView(int position,View convertView,  ViewGroup parent) {
   View ListItemView = convertView;

   if(ListItemView == null)
   {
       ListItemView = LayoutInflater.from(getContext()).inflate(R.layout.list_item,parent,false);
   }
     FoodItemclass foodItemclass = getItem(position);

       TextView itename = ListItemView.findViewById(R.id.ItemnameId);
       itename.setText(foodItemclass.getmItemName());

       TextView itemprice = ListItemView.findViewById(R.id.ItemPriceId);
       itemprice.setText(foodItemclass.getmItemPrice());

   return ListItemView;
}

}

主类： 公共类 RiceCategory 扩展 AppCompatActivity {

private DatabaseReference databaseReference;
private FoodItemAdapter mFoodAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_rice_category);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    databaseReference = FirebaseDatabase.getInstance().getReference("UpdatedMenu").child("Noodles & Rice");
    final List<FoodItemclass> foodItemclasses = new ArrayList<>();
    mFoodAdapter =new FoodItemAdapter(this,foodItemclasses);
    ListView mListview = (ListView)findViewById(R.id.listview) ;
    mListview.setAdapter(mFoodAdapter);

    android.support.v7.app.ActionBar actionBar =getSupportActionBar();
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    actionBar.setTitle("Rice");
    databaseReference.addChildEventListener(new ChildEventListener() {
        @Override
         public void onChildAdded( DataSnapshot dataSnapshot,  String s) {
                 FoodItemclass food = dataSnapshot.getValue(FoodItemclass.class);
                 foodItemclasses.add(food);
                 mFoodAdapter.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) {

        }
    });
}

我真的陷入了困境，我尝试了不同的方法，但没有得到任何结果，所以我在这里发布，如果你发现代码中有任何错误，请告诉你们，所以请在 cmets 上发布并改正。我会非常感谢你

Answer 1

您需要将项目布局传递给数组适配器构造函数。但是您将其发送为 0

public FoodItemAdapter(Activity context, List<FoodItemclass> arrayList)
{
    super(context,0,arrayList);
}

将 0 更改为 android.R.layout.simple_list_item_1 或一些自定义视图 xml

Answer 2

你能不能试着改变你的父子从前。面饭改成面_&_饭？