列表视图被填充重复项

时间:2021-04-06 03:14:40

标签: android-studio parse-platform android-listview custom-adapter

我创建了一个数组列表,并将元素从从解析服务器接收到的值/对象推送到数组。现在主活动中的 listView 被重复值填充。列表项的数量(使用自定义适配器)等于数组长度。但是当我记录数组列表时,数组值中的值是唯一的并且不会重复。

package com.example.fooddeliveryapp;

import androidx.appcompat.app.AppCompatActivity;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

import com.parse.FindCallback;
import com.parse.GetDataCallback;
import com.parse.ParseException;
import com.parse.ParseFile;
import com.parse.ParseObject;
import com.parse.ParseQuery;

import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import java.util.List;

public class ListFoods extends AppCompatActivity {

    ListView listView;
    ArrayList<Bitmap> images = new ArrayList<Bitmap>();
    ArrayList<String> names = new ArrayList<String>();
    ArrayList<String> restaurants = new ArrayList<String>();

    //custom adapter
    class custom extends BaseAdapter {

        @Override
        public int getCount() {
            return names.size();
        }

        @Override
        public Object getItem(int position) {
            return null;
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }

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

            View v = getLayoutInflater().inflate(R.layout.list_foods , null);
            ImageView image = v.findViewById(R.id.foodImage);
            TextView name = v.findViewById(R.id.foodName);
            TextView restaurant = v.findViewById(R.id.restaurantName);

            if(images.size() > 0){

                image.setImageBitmap(images.get(position));
                name.setText(names.get(position));
                restaurant.setText(restaurants.get(position));

            }


            return v;
        }
    }


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

        custom adapter = new custom();

        //access views
        listView = findViewById(R.id.listItems);

        //get values from parse Server
        ParseQuery query = ParseQuery.getQuery("Foods");

        query.findInBackground(new FindCallback<ParseObject>() {
            @Override
            public void done(List<ParseObject> objects, ParseException e) {
                for( ParseObject object : objects){
                    String name = object.getString("names");
                    String restaurant = object.getString("restaurants");

                    //add to array
                    names.add(name);
                    restaurants.add(restaurant);

                    //file
                    ParseFile file = object.getParseFile("image");
                    file.getDataInBackground(new GetDataCallback() {
                        @Override
                        public void done(byte[] data, ParseException e) {
                            if(e == null && data != null){
                                Bitmap bitmap = BitmapFactory.decodeByteArray(data , 0 , data.length);
                                images.add(bitmap);
                            }
                        }
                    });
                }

                Log.i("names" , names.toString());

                listView.setAdapter(adapter);

            }
        });





    }
}

请原谅我有史以来最糟糕的解释。这是输出屏幕截图 output

注意 - 列表项中的值是列表项中的默认值。这是列表项的xml代码

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/foodImage"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_marginStart="16dp"
        android:layout_marginEnd="295dp"
        android:scaleType="centerCrop"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:srcCompat="@drawable/melon"
        tools:layout_editor_absoluteY="29dp" />

    <TextView
        android:id="@+id/name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="21dp"
        android:layout_marginEnd="209dp"
        android:fontFamily="sans-serif-thin"
        android:text="Name: "
        android:textSize="20sp"
        android:textStyle="bold"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toEndOf="@+id/foodImage"
        tools:layout_editor_absoluteY="51dp" />

    <TextView
        android:id="@+id/foodName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="101dp"
        android:text="WaterMelon"
        android:textSize="20sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/name"
        tools:layout_editor_absoluteY="51dp" />

    <TextView
        android:id="@+id/restaurant"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="22dp"
        android:layout_marginTop="10dp"
        android:text="Restaurant: "
        android:textSize="20sp"
        app:layout_constraintEnd_toStartOf="@+id/restaurantName"
        app:layout_constraintStart_toEndOf="@+id/foodImage"
        app:layout_constraintTop_toBottomOf="@+id/name" />

    <TextView
        android:id="@+id/restaurantName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_marginEnd="59dp"
        android:text="some hub"
        android:textSize="20sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/restaurant"
        app:layout_constraintTop_toBottomOf="@+id/foodName" />
</androidx.constraintlayout.widget.ConstraintLayout>

0 个答案:

没有答案