//匯入依賴

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

//首先在activity頁面新增兩個水平的RecyclerView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="horizontal"
    tools:context=".MainActivity">
    <android.support.v7.widget.RecyclerView
        android:layout_width="100dp"
        android:layout_height="match_parent"
        android:id="@+id/recyr_left"/>
    <android.support.v7.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/recy_right"/>

</LinearLayout>
 

//在MainActivity頁面進行訪問介面以及建立介面卡的基本操作

package soexample.umeng.com.fenlei01;

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

import com.google.gson.Gson;

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

import soexample.umeng.com.fenlei01.adapter.MyLeftAdapter;
import soexample.umeng.com.fenlei01.adapter.MyRightAdapter;
import soexample.umeng.com.fenlei01.bean.ShopLeftBean;
import soexample.umeng.com.fenlei01.bean.ShopRightBean;
import soexample.umeng.com.fenlei01.utils.OkHttpHelper;

public class MainActivity extends AppCompatActivity {

    private RecyclerView recy_left;
    private RecyclerView recy_right;
    private List<ShopLeftBean.DataBean> leftbean = new ArrayList<>();
    private MyLeftAdapter myLeftAdapter;
    private int cid = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate( savedInstanceState );
        setContentView( R.layout.activity_main );
        recy_left = findViewById( R.id.recyr_left );
        recy_right = findViewById( R.id.recy_right );


        LinearLayoutManager linearLayoutManager = new LinearLayoutManager( this );
        linearLayoutManager.setOrientation( LinearLayoutManager.VERTICAL );
        recy_left.setLayoutManager( linearLayoutManager );

        myLeftAdapter = new MyLeftAdapter( MainActivity.this, leftbean );
        recy_left.setAdapter( myLeftAdapter );
        leftbean = new ArrayList<>();
        myLeftAdapter.setItemClick( new MyLeftAdapter.ItemClickListener() {
            @Override
            public void onItemClickListener(int position) {
                int id = leftbean.get( position ).getCid();
                doHttpRight( id );
            }
        } );
        /*myLeftAdapter.setListener( new MyLeftAdapter.ItemClickListener() {
            @Override
            public void onItemClick(int position) {
                int id = leftbean.get( position ).getCid();
                doHttpRight( id );
            }
        } );*/
        doHttpLeft();
        LinearLayoutManager linearLayoutManager1 = new LinearLayoutManager( this );
        linearLayoutManager1.setOrientation( LinearLayoutManager.VERTICAL );
        recy_right.setLayoutManager( linearLayoutManager1 );


    }

    private void doHttpLeft() {
        new OkHttpHelper().get( "http://www.zhaoapi.cn/product/getCatagory" ).result( new OkHttpHelper.OkHttpHelperListener() {
            @Override
            public void Success(String data) {
                ShopLeftBean shopLeftBean = new Gson().fromJson( data, ShopLeftBean.class );
                leftbean = shopLeftBean.getData();
                myLeftAdapter.setList( leftbean );
            }

            @Override
            public void Error() {

            }
        } );
        doHttpRight( cid );
    }

    private void doHttpRight(int cid) {
        new OkHttpHelper().get( "http://www.zhaoapi.cn/product/getProductCatagory?cid=" + cid ).result( new OkHttpHelper.OkHttpHelperListener() {
            @Override
            public void Success(String data) {
                ShopRightBean shopRightBean = new Gson().fromJson( data, ShopRightBean.class );
                List<ShopRightBean.DataBean> rightbean = shopRightBean.getData();
                MyRightAdapter rightAdapter = new MyRightAdapter( MainActivity.this, rightbean );
                recy_right.setAdapter( rightAdapter );
            }

            @Override
            public void Error() {

            }
        } );
    }


}
 

//左邊列表展示的的介面卡   

package soexample.umeng.com.fenlei01.adapter;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

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

import soexample.umeng.com.fenlei01.MainActivity;
import soexample.umeng.com.fenlei01.R;
import soexample.umeng.com.fenlei01.bean.ShopLeftBean;

public class MyLeftAdapter extends RecyclerView.Adapter<MyLeftAdapter.MyViewHolder>{
    private Context context;
    private List<ShopLeftBean.DataBean> leftbean = new ArrayList<>(  );
    public MyLeftAdapter(MainActivity mainActivity, List<ShopLeftBean.DataBean> leftbean) {
        context = mainActivity;
        this.leftbean = leftbean;
    }

    @NonNull
    @Override
    public MyLeftAdapter.MyViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View view = View.inflate( context, R.layout.item,null);
        MyViewHolder myViewHolder = new MyViewHolder( view );
        myViewHolder.shopName = view.findViewById( R.id.text_shop_Name );
        return myViewHolder;
    }

    @Override
    public void onBindViewHolder(@NonNull MyLeftAdapter.MyViewHolder myViewHolder, final int i) {
        myViewHolder.shopName.setText( leftbean.get( i ).getName() );
        myViewHolder.shopName.setOnClickListener( new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               listener.onItemClickListener( i );
            }
        } );
    }

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

    public void setList(List<ShopLeftBean.DataBean> list) {
        leftbean = list;
        notifyDataSetChanged();
    }

    public class MyViewHolder extends RecyclerView.ViewHolder {
        public MyViewHolder(@NonNull View itemView) {
            super( itemView );
        }
        TextView shopName;
    }
//由於RecyclerView本身沒有點選事件 所以通過介面回撥的方式進進行獲取id
    private ItemClickListener listener;
    public void setItemClick(ItemClickListener listener){
        this.listener = listener;
    }
    public interface ItemClickListener{
        void onItemClickListener(int position);
    }
}
 

//右邊展示的介面卡

package soexample.umeng.com.fenlei.adapter;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.util.List;

import soexample.umeng.com.fenlei.R;
import soexample.umeng.com.fenlei.bean.RightBean;

public class RightAdapter extends RecyclerView.Adapter<RightAdapter.MyViewHolder>{
    private List<RightBean.DataBean> list;
    private Context context;

    public RightAdapter(List<RightBean.DataBean> list, Context context) {
        this.list = list;
        this.context = context;
    }

    @NonNull
    @Override
    public RightAdapter.MyViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View view = View.inflate( context, R.layout.right_layout,null );
        MyViewHolder viewHolder = new MyViewHolder( view );
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(@NonNull RightAdapter.MyViewHolder myViewHolder, int i) {
        myViewHolder.textView.setText( list.get( i ).getName() );
        List<RightBean.DataBean.ListBean> listBeans = this.list.get( i ).getList();
        GridLayoutManager layoutManager = new GridLayoutManager( context,3 );
        myViewHolder.recyclerView.setLayoutManager( layoutManager );
        myViewHolder.recyclerView.setAdapter( new ShopAdapter( listBeans,context ) );
    }

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

    public class MyViewHolder extends RecyclerView.ViewHolder {
        TextView textView;
        RecyclerView recyclerView;
        public MyViewHolder(@NonNull View itemView) {
            super( itemView );
            textView = itemView.findViewById( R.id.text_title );
            recyclerView = itemView.findViewById( R.id.recy_shop );
        }
    }
}

//右邊 涉及到了兩個RecyclerView

//所以要進行巢狀

//這裡是巢狀的介面卡

package soexample.umeng.com.fenlei01.adapter;

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

import com.bumptech.glide.Glide;

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

import soexample.umeng.com.fenlei01.R;
import soexample.umeng.com.fenlei01.bean.ShopRightBean;

public class MyRightItemAdapter extends RecyclerView.Adapter<MyRightItemAdapter.MyViewHolder> {
    private Context context;
    private List<ShopRightBean.DataBean> rightbean = new ArrayList<>();

    public MyRightItemAdapter(Context context, List<ShopRightBean.DataBean> rightbean) {
        this.context = context;
        this.rightbean = rightbean;
    }

    @NonNull
    @Override
    public MyRightItemAdapter.MyViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View view = View.inflate( context, R.layout.right_item_2, null );
        MyViewHolder myViewHolder = new MyViewHolder( view );
        myViewHolder.imageView = view.findViewById( R.id.imageView );
        myViewHolder.textView = view.findViewById( R.id.textView );
        return myViewHolder;
    }

    @Override
    public void onBindViewHolder(@NonNull MyRightItemAdapter.MyViewHolder myViewHolder, int i) {
        myViewHolder.textView.setText( rightbean.get( i ).getList().get( i ).getName() );
        Glide.with( context ).load( rightbean.get( i ).getList().get( i ).getIcon() ).into(myViewHolder.imageView );
    }

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

    public class MyViewHolder extends RecyclerView.ViewHolder {
        public MyViewHolder(@NonNull View itemView) {
            super( itemView );
        }

        ImageView imageView;
        TextView textView;
    }
}

//成品打給就是這個樣了了

//一些動畫點選還未操作 粗糙實現 慎用