android学习之RecyclerView的简单使用

用一个来自于《第一行代码》的简单例子说明：
Fruit.java

package com.example.luobo.recyclerviewtest;
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;
    }
}

FruitAdapter.java

package com.example.luobo.recyclerviewtest;

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 android.widget.Toast;

import java.util.List;

public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder> {
    private List<Fruit> mFruitList;

    static class ViewHolder extends RecyclerView.ViewHolder{
        ImageView fruitImage;
        TextView fruitName;
        View fruitView;

        public ViewHolder(View view){
            super(view);
            fruitView = view;
            fruitImage = (ImageView)view.findViewById(R.id.fruit_image);
            fruitName = (TextView)view.findViewById(R.id.fruit_name);
        }

    }
    public FruitAdapter(List<Fruit> fruitList){
        mFruitList = fruitList;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fruit_item,parent,false);

        final ViewHolder viewHolder = new ViewHolder(view);
        viewHolder.fruitView.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View view) {
                int position = viewHolder.getAdapterPosition();
                Fruit fruit = mFruitList.get(position);
                Toast.makeText(view.getContext(),"You clicked view: "+fruit.getName(),Toast.LENGTH_SHORT).show();
            }
        });
        viewHolder.fruitImage.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View view) {
                int position = viewHolder.getAdapterPosition();
                Fruit fruit = mFruitList.get(position);
                Toast.makeText(view.getContext(),"You clicked image: "+fruit.getName(),Toast.LENGTH_SHORT).show();
            }
        });
        return viewHolder;
    }


    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        Fruit fruit = mFruitList.get(position);
        holder.fruitImage.setImageResource(fruit.getImageId());
        holder.fruitName.setText(fruit.getName());
    }

    @Override
    public int getItemCount() {
        return mFruitList.size();
    }
}

RecyclerViewActivity.java

package com.example.luobo.recyclerviewtest;

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

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

public class RecyclerViewActivity extends AppCompatActivity {
    private String[] data = {"Apple","Banana","Orange","Watermelon","Pear","Grape","Pinapple",
            "Strawberry","Cherry","Mango","Apple","Banana","Orange","Watermelon","Pear","Grape",
            "Pinapple", "Strawberry","Cherry","Mango"};
    private List<Fruit> fruitList = new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_recycler_view);
        initFruits();
        RecyclerView recyclerView = (RecyclerView)findViewById(R.id.recycler_view_test);
//        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
//        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL);
        recyclerView.setLayoutManager(layoutManager);
        FruitAdapter adapter = new FruitAdapter(fruitList);
        recyclerView.setAdapter(adapter);
    }
    public void initFruits(){
        for (int i = 0;i<2;i++ )
        {
            for (int j = 0 ; j < data.length ; j++)
            {
                Fruit object = new Fruit(getRandomLengthName(data[j]),R.drawable.image2);
                fruitList.add(object);
            }
        }
    }
    private String getRandomLengthName(String name){
        Random random = new Random();
        int length = random.nextInt(20)+1;
        StringBuilder builder = new StringBuilder();
        for (int i = 0;i < length;i++){
            builder.append(name);
        }
        return builder.toString();
    }
}

activity_recyler.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <android.support.v7.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/recycler_view_test">

    </android.support.v7.widget.RecyclerView>
</LinearLayout>

fruit_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="5dp">
    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/fruit_image"
        android:layout_gravity="center_horizontal"/>
    <TextView
        android:id="@+id/fruit_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="left"
        android:layout_marginTop="10dp"/>
</LinearLayout>

在app文件夹下的build.grandle中的dependencies添加外部支持

compile 'com.android.support:recyclerview-v7:26.+'//最新版本就行