引入包

implementation 'com.squareup.okhttp3:okhttp:3.12.3'
implementation 'com.android.support:recyclerview-v7:28.0.0'
implementation 'com.github.bumptech.glide:glide:3.7.0'

权限

<uses-permission android:name="android.permission.INTERNET" />

MainActivity.java

public class MainActivity extends AppCompatActivity {
    private List<Item> items=new ArrayList<>();
    private  ItemAdapter adapter;
    private View view;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        RecyclerView rv=findViewById(R.id.rv);
        LinearLayoutManager manager=new LinearLayoutManager(this);
    //    GridLayoutManager manager1=new GridLayoutManager(this,3);表格布局
        manager.setOrientation(LinearLayoutManager.VERTICAL);
        rv.setLayoutManager(manager);
        adapter=new ItemAdapter(items,this);
        rv.setAdapter(adapter);

       OkHttpClient client=new OkHttpClient();
        Request request=new Request.Builder()
                .url("https://api.myjson.com/bins/apm1f")
                .build();
        client.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call,IOException e) {
                Log.d("错误","onFailure:"+e.toString());
            }
            @Override
            public void onResponse(Call call, Response response) throws IOException {
                try {
                    String data=response.body().string();
                    JSONArray jsonArray=new JSONArray(data);
                    for (int i=0;i<jsonArray.length();i++){
                        JSONObject jso=jsonArray.getJSONObject(i);
                        Item item=new Item();
                        item.setName(jso.getString("name"));
                        item.setImg(jso.getString("img"));
                        items.add(item);
                    }
                      runOnUiThread(new Runnable() {
                          @Override
                          public void run() {
                              adapter.notifyDataSetChanged();
                          }
                      });
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        });
    }
    public void bottom(View view){
        this.view = view;
        Toast.makeText(MainActivity.this,"查看详情",Toast.LENGTH_SHORT).show();
         Intent intent=new Intent(MainActivity.this,Main2Activity.class);
         startActivity(intent);}

activity_main.xml

<?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"
    tools:context=".MainActivity" >

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

</LinearLayout>

item_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal">
    <ImageView
        android:id="@+id/imgTv"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="120dp" />
<TextView
    android:textSize="24dp"
    android:id="@+id/nameTv"
    android:layout_weight="1"
    android:layout_width="0dp"
    android:layout_height="50dp" />
    <Button
        android:onClick="bottom"
        android:layout_weight="1"
        android:text="查看详情"
        android:layout_width="0dp"
        android:layout_height="50dp" />
</LinearLayout>

Item.java

public class Item {
    private String name;
    private String img;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getImg() {
        return img;
    }

    public void setImg(String img) {
        this.img = img;
    }
}

ItemHoder.java

public class ItemHoder extends RecyclerView.ViewHolder {
    TextView nameTv;
    ImageView imgTv;
    public ItemHoder( View itemView) {
        super(itemView);
        nameTv=itemView.findViewById(R.id.nameTv);
        imgTv=itemView.findViewById(R.id.imgTv);
    }
}

ItemAdapter.java

public class ItemAdapter extends RecyclerView.Adapter<ItemHoder> {
  private List<Item> items;
  private Context context;
    public ItemAdapter(List<Item> items,Context context){
        this.items=items;
        this.context=context;
    }
    @Override
    public ItemHoder onCreateViewHolder(ViewGroup viewGroup, int i) {
       View view= LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_layout,viewGroup,false);
        return new ItemHoder(view);
    }

    @Override
    public void onBindViewHolder(ItemHoder itemHoder, int position) {
          itemHoder.nameTv.setText(items.get(position).getName());
          Glide.with(context).load(items.get(position).getImg()).into(itemHoder.imgTv);
    }
    @Override
    public int getItemCount() {
        return items.size();
    }
}

Main2Activity.java

public class Main2Activity extends AppCompatActivity {
    private TextView textView;
    private Button bu1;
    private Button bu2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        textView=findViewById(text);bu2=findViewById(R.id.bu2);
        bu1=findViewById(R.id.bu1);


        bu2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(Main2Activity.this,MainActivity.class);
                startActivity(intent);
            }
        });
    }

    public void but1(View view) {
        Toast.makeText(Main2Activity.this,"购买",Toast.LENGTH_SHORT).show();
        Intent intent=new Intent(Main2Activity.this,Main3Activity.class);
        startActivity(intent);
    }
}

activity_main2.xml

<?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"
    tools:context=".Main2Activity" android:orientation="vertical">
    <TextView
        android:textSize="30dp"
        android:text="商品详情"
        android:layout_gravity="center"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
<ImageView
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:src="@drawable/one"/>
    <TextView
        android:id="@+id/text"
        android:text="促销价:￥129.90"
        android:textSize="25dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <TextView
        android:textSize="20dp"
        android:text="商品名称:零食大礼包                                        商品编号：6401663
     商品产地：中国大陆  类别：其它国产/进口国产"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Button
        android:onClick="but1"
        android:id="@+id/bu1"
        android:layout_marginTop="20dp"
        android:layout_gravity="center"
        android:text="购买"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/bu2"
        android:layout_gravity="center"
        android:text="返回"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

Main3Activity.java

public class Main3Activity extends AppCompatActivity {
    private Button b3;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
        b3=findViewById(R.id.b3);
        b3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(Main3Activity.this,Main2Activity.class);
                startActivity(intent);
            }
        });
    }
}

activity_main3.xml

<TextView
        android:textSize="35dp"
        android:text="请用微信扫码支付"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
<ImageView
    android:layout_marginLeft="50dp"
    android:layout_marginTop="20dp"
    android:src="@drawable/tt"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />
    <Button
        android:id="@+id/b3"
        android:text="返回"
        android:layout_marginRight="30dp"
        android:layout_gravity="right"
        android:layout_marginTop="50dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />