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