這篇RecyclerView與前幾篇介紹ListView相似，主要是用清單條列出來，讓使用者簡單明瞭，
RecyclerView是Google在Android5.0時推出，目的是優化ListView相關程式及效能。

今天這篇利用RecyclerView來做一個範例
要利用RecyclerView要先在Gradle Scripts/build.grade(.app)裡的dependencies新增

implementation 'androidx.recyclerview:recyclerview:1.1.0'

接著在activity_main.xml裡新增recyclerView元件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycleView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</RelativeLayout>

接著新增recyclerView要顯示的排版xml檔

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <androidx.cardview.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <ImageView
                android:id="@+id/myImageView"
                android:layout_width="100dp"
                android:layout_height="100dp"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:srcCompat="@drawable/ic_launcher_background"
                tools:ignore="VectorDrawableCompat" />

            <TextView
                android:id="@+id/myText1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="24dp"
                android:layout_marginLeft="24dp"
                android:layout_marginTop="16dp"
                android:text="Title"
                android:textSize="24sp"
                android:textStyle="bold"
                app:layout_constraintStart_toEndOf="@+id/myImageView"
                app:layout_constraintTop_toTopOf="parent" />

            <TextView
                android:id="@+id/myText2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="24dp"
                android:layout_marginLeft="24dp"
                android:text="Description"
                android:textSize="16sp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toEndOf="@+id/myImageView"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintVertical_bias="0.813" />
        </androidx.constraintlayout.widget.ConstraintLayout>

    </androidx.cardview.widget.CardView>
</androidx.constraintlayout.widget.ConstraintLayout>

排版設定好可以透過values/strings來設定要顯示的文字

<resources>
    <string name="app_name">Recycleview</string>
    
    <string-array name="progrmming_languages">
        <item>可麗露</item>
        <item>舒芙蕾</item>
        <item>瑪德蓮</item>
        <item>馬卡龍</item>
        <item>泡芙</item>
    </string-array>
    
    <string-array name="description">
        <item>是一種小型的法式甜點，表層則是硬脆\n又厚實的褐色焦糖外殼，內部是半融化\n狀的蛋糕糊，散發著酒香和香草味。</item>
        <item>是一種源自法國的甜品，經烘焙後質感\n輕而蓬鬆</item>
        <item>是一種傳統的貝殼形狀的小蛋糕，來自\n於法國東北部洛林大區的兩個市鎮科梅\n爾西和利韋爾丹</item>
        <item>是一種用色彩繽紛絢麗的法國甜品，外\n殼堅硬但易碎，內陷黏稠扎實</item>
        <item>是一種源自法國的球形糕點，蓬鬆張孔\n的麵皮中包裹鮮奶油、巧克力乃至冰淇\n淋</item>
    </string-array>
</resources>

接著建立Adapter來控管每個item的顯示設定，我們自訂了一個名為MyAdapter的類別，此類別繼承了 RecyclerView.Adapter

package com.example.recycleview;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {

    String data1[],data2[];
    int images[];
    Context context;
    public MyAdapter(Context ct,String s1[],String s2[],int img[]){
        context = ct;
        data1 = s1;
        data2 = s2;
        images = img;
    }
    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater inflater = LayoutInflater.from(context);
        View view = inflater.inflate(R.layout.my_row,parent,false);
        return new MyViewHolder(view);
    }
    @Override
    //透過 position 參數指定每個item所用到的資料
    public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {
        holder.myText1.setText(data1[position]);
        holder.myText2.setText(data2[position]);
        holder.myImage.setImageResource(images[position]);
    }
    @Override
    public int getItemCount() {
        return images.length;
    }
    public class MyViewHolder extends RecyclerView.ViewHolder{
        TextView myText1,myText2;
        ImageView myImage;
        public MyViewHolder(@NonNull View itemView) {
            super(itemView);
            myText1 = itemView.findViewById(R.id.myText1);
            myText2 = itemView.findViewById(R.id.myText2);
            myImage = itemView.findViewById(R.id.myImageView);
        }
    }
}

設定完Adapter後就可以在MainActivity.java中設定RecyclerView

package com.example.recycleview;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.os.Bundle;

public class MainActivity extends AppCompatActivity {
    RecyclerView recycleView;


    String s1[] ,s2[];
    int images[] = {R.drawable.coco,R.drawable.su,R.drawable.lan,R.drawable.mar,R.drawable.pabu};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        recycleView = findViewById(R.id.recycleView);
        s1 = getResources().getStringArray(R.array.progrmming_languages);
        s2 = getResources().getStringArray(R.array.description);

        MyAdapter myAdapter = new MyAdapter(this,s1,s2,images);
        recycleView.setAdapter(myAdapter);
        recycleView.setLayoutManager(new LinearLayoutManager(this));
    }
}

這樣就完成囉