RecyclerView 的基本用法

activity_recycler_view.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_recycler_vew"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.wonderful.myfirstcode.custom_controls.recycler_view.RecyclerVewActivity">

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

建立一個水果 Fruit 類

public class Fruit {
    private String name; // 水果名
    private int imageId; // 水果圖片id

    public Fruit(String name, int imageId) {
        this.name = name;
        this.imageId = imageId;
    }

    public String getName() {
        return name;
    }

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

    public int getImageId() {
        return imageId;
    }

    public void setImageId(int imageId) {
        this.imageId = imageId;
    }
}
 

水果的佈局 fruit_item.xml：

<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <ImageView
        android:id="@+id/fruit_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <TextView
        android:id="@+id/fruit_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:layout_marginLeft="10dp"/>

</LinearLayout>
 

為 RecyclerView 準備一個介面卡，新建 FruitAdapter 類，讓這個介面卡繼承RecyclerView.Adapter，並將泛型指定為 FruitAdapter.ViewHolder。其中，ViewHolder 是我們在 FruitAdapter 中定義的一個內部類

public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder>{

    private List<Fruit> mFruitList;

    /**
     * 建構函式，用於把要展示的資料來源傳進來
     * @param mFruitList
     */
    public FruitAdapter(List<Fruit> mFruitList) {
        this.mFruitList = mFruitList;
    }

    /**
     * 建立ViewHolder例項
     * @param parent
     * @param viewType
     * @return
     */
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fruit_item,parent,false);
        ViewHolder holder = new ViewHolder(view);
        return holder;
    }

    /**
     * 對RecyclerView子項的資料進行賦值
     * @param holder
     * @param position
     */
    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        Fruit fruit = mFruitList.get(position);
        holder.fruitImage.setImageResource(fruit.getImageId());
        holder.fruitName.setText(fruit.getName());
    }

    /**
     * 子項的數目
     * @return
     */
    @Override
    public int getItemCount() {
        return mFruitList.size();
    }

    /**
     * 內部類，ViewHolder要繼承自 RecyclerView.ViewHolder
     */
    public class ViewHolder extends RecyclerView.ViewHolder{
        ImageView fruitImage;
        TextView fruitName;

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

開始使用 RecyclerView 

public class RecyclerVewActivity extends AppCompatActivity {

    private List<Fruit> fruitList = new ArrayList<>();

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

         // 初始化水果資料
        initFruits();
        // 獲取RecyclerView的例項
        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        // LayoutManager用於指定RecyclerView的佈局方式，LinearLayoutManager表示線性佈局
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
        // 建立FruitAdapter的例項
        FruitAdapter adapter = new FruitAdapter(fruitList);
        // 設定介面卡
        recyclerView.setAdapter(adapter);
    }

    private void initFruits() {
        for (int i = 0;i < 2;i++){
            Fruit apple = new Fruit("Apple",R.drawable.pic_apple);
            fruitList.add(apple);
            Fruit banana = new Fruit("Banana",R.drawable.pic_banana);
            fruitList.add(banana);
            Fruit orange = new Fruit("orange",R.drawable.pic_orange);
            fruitList.add(orange);
            Fruit watermelon = new Fruit("watermelon",R.drawable.pic_watermelon);
            fruitList.add(watermelon);
            Fruit grape = new Fruit("grape",R.drawable.pic_grape);
            fruitList.add(grape);
            Fruit pineapple = new Fruit("pineapple",R.drawable.pic_pineapple);
            fruitList.add(pineapple);
            Fruit strawberry = new Fruit("strawberry",R.drawable.pic_strawberry);
            fruitList.add(strawberry);
            Fruit cherry = new Fruit("cherry",R.drawable.pic_cherry);
            fruitList.add(cherry);
            Fruit mango = new Fruit("mango",R.drawable.pic_mango);
            fruitList.add(mango);
        }
    }
}