Android开发学习之RecyclerView

1、在app/build.gradle中添加RecyclerView依赖

implementation 'com.android.support:recyclerview-v7:28.0.0'

注意依赖版本号

2、布局文件activity_main.xml引入RecycleView

<android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>

3、泛型类型Fruit.java

package com.example.lalala.recyclerviewdemo;

public class Fruit {
    private String name;
    private int imageId;
    public Fruit(String name,int imageId){
        this.name = name;
        this.imageId = imageId;
    }

    public String getName() {
        return name;
    }

    public int getImageId() {
        return imageId;
    }
}

4、布局fruit_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <ImageView
        android:id="@+id/fruit_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/fruit_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:layout_marginLeft="10dp"
        />
</LinearLayout>

5、适配器FruitAdapter.java

package com.example.lalala.recyclerviewdemo;

import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.List;

public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder> {
    //适配器保存的数据
    private List<Fruit> mFruitList;
    //view容器类，ViewHolder容纳view
    static class ViewHolder extends RecyclerView.ViewHolder{
        ImageView imageView;
        TextView textView;
        public ViewHolder(View view){
            super(view);
            imageView = (ImageView)view.findViewById(R.id.fruit_image);
            textView = (TextView)view.findViewById(R.id.fruit_name);
        }
    }
    //构造函数初始化适配器
    public FruitAdapter(List<Fruit> fruitList){
        mFruitList = fruitList;
    }
    //创建ViewHolder
    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.fruit_item,viewGroup,false);
        ViewHolder viewHolder = new ViewHolder(view);
        return viewHolder;
    }
    //绑定数据到ViewHolder
    @Override
    public void onBindViewHolder(@NonNull ViewHolder viewHolder, int i) {
        Fruit fruit = mFruitList.get(i);
        viewHolder.imageView.setImageResource(fruit.getImageId());
        viewHolder.textView.setText(fruit.getName());
    }
    //返回子项个数
    @Override
    public int getItemCount() {
        return mFruitList.size();
    }
}

6、配置并使用RecyclerView

package com.example.lalala.recyclerviewdemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

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

public class MainActivity extends AppCompatActivity {

    private List<Fruit> fruitList = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initFruit();
        //使用RecyclerView
        RecyclerView recyclerView = (RecyclerView)findViewById(R.id.recycler_view);
        //布局管理器
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
        FruitAdapter adapter = new FruitAdapter(fruitList);
        recyclerView.setAdapter(adapter);
    }
    private void initFruit(){
        for(int i=0;i<8;i++){
            Fruit apple = new Fruit("Apple",R.mipmap.ic_launcher);
            fruitList.add(apple);
            Fruit pear = new Fruit("Pear",R.mipmap.ic_launcher);
            fruitList.add(pear);
            Fruit banana = new Fruit("Banana",R.mipmap.ic_launcher);
            fruitList.add(banana);
        }
    }
}

7、大功告成，运行截图