RecyclerView 的使用

RecyclerView提供了三种布局管理器

1、LinearLayoutManager:线性布局管理器，支持水平和垂直效果。
2、GridLayoutManager:网格布局管理器，支持水平和垂直效果。
3、StaggeredGridLayoutManager:分布型管理器，瀑布流效果Animations(动画)效果


 

注意 添加的依赖

compile 'com.android.support:recyclerview-v7:23.2.0'
compile 'com.squareup.okio:okio:1.5.0'
compile 'com.squareup.okhttp3:okhttp:3.2.0'
compile 'com.squareup.picasso:picasso:2.5.1'

XML 文件

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.bwei.recyclerview.MainActivity">

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

</android.support.constraint.ConstraintLayout>

 具体代码

package com.bwei.recyclerview;

import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
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 com.squareup.picasso.Picasso;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class MainActivity extends AppCompatActivity {
    String url = "http://result.eolinker.com/iYXEPGn4e9c6dafce6e5cdd23287d2bb136ee7e9194d3e9?uri=one";
    private RecyclerView rv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //抽取一个获取数据的方法
        getData();
        //找控件
        rv = (RecyclerView) findViewById(R.id.rv);

        //布局管理器
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
        //把布局管理器设置给RecyclerView
        rv.setLayoutManager(linearLayoutManager);

        //创建适配器


    }

    //获取数据
    private void getData() {
        //创建OkHttpClient
            OkHttpClient okHttpClient = new OkHttpClient();
        //创建Request
        Request request = new Request.Builder().url(url).build();
        //得到Call
        Call call = okHttpClient.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {

            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                final String json = response.body().string();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            JSONObject jsonObject = new JSONObject(json);
                            JSONArray data = jsonObject.getJSONArray("data");
                            //创建适配器
                            MyAdapter adapter = new MyAdapter(MainActivity.this, data);
                            rv.setAdapter(adapter);
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }

                    }
                });
            }
        });

    }

    public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
        Context context;
        JSONArray data;

        public MyAdapter(Context context, JSONArray data) {
            this.context = context;
            this.data = data;
        }

        @Override
        public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            //把View绑定到ViewHolder上
            View view = LayoutInflater.from(MainActivity.this).inflate(R.layout.item, parent, false);
            MyViewHolder holder = new MyViewHolder(view);

            return holder;
        }

        //绑定数据给控件
        @Override
        public void onBindViewHolder(MyViewHolder holder, int position) {
            try {
                JSONObject jsonObject = data.getJSONObject(position);
                String title = jsonObject.getString("title");
                String image_url = jsonObject.getString("image_url");
                holder.tv_title.setText(title);
                //一行代码实现图片显示
                Picasso.with(context).load(image_url).into(holder.iv_head);

            } catch (JSONException e) {
                e.printStackTrace();
            }

        }

        //获取数据的数量
        @Override
        public int getItemCount() {
            return data.length();
        }

        //MyViewHolder应该是适配器MyAdapter的内部类
        public class MyViewHolder extends RecyclerView.ViewHolder {
            //声明控件
            public ImageView iv_head;
            public TextView tv_title;

            // 自定义的ViewHolder，持有每个Item的的所有界面元素
            public MyViewHolder(View view) {
                super(view);
                //获取控件赋值
                iv_head = view.findViewById(R.id.iv_head);
                tv_title = view.findViewById(R.id.tv_title);
            }
        }
    }


}