1. 程式人生 > >Android開發:Recycler的使用流程總結——基於《第一行程式碼》

Android開發:Recycler的使用流程總結——基於《第一行程式碼》

  1. app/build.gradle檔案:
//dependencies閉包中新增
compile 'com.android.support:recyclerview-v7:24.2.1'
  1. 新增RecyclerView:
<android.support.v7.widget.RecyclerView
    android:id="@+id/recycler_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
/>
  1. 建立子項:
<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>
  1. 建立實體類:
public class Fruit{
    //屬性
    private String name;
    private int imageId;
    
    //建構函式
    public Fruit(String name, int imageId){
        this.name = name;
        this.imageId = imageId;
    }
    
    //getter和setter 略
}
  1. 建立介面卡:
public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder>{
    private List<Fruit> mFruitList;
    
    static class ViewHolder extends RecyclerView.ViewHolder{
        View fruitView;
        ImageView fruitImage;
        TextView fruitName;
        
        public ViewHolder(View view){
            super(view);
            fruitView = view;
            fruitImage = view.findViewById(R.id.fruit_image);
            fruitName = view.findViewById(R.id.fruit_name);
        }
    }
    
    public FruitAdapter(List<Fruit> fruitList){
        mFruitList = fruitList;
    }
    
    //用於建立ViewHolder例項
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType){
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fruit_item, parent, false);
        final ViewHolder holder = new ViewHolder(view);
        holder.fruitView.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                int position = holder.getAdapterPosition();
                Fruit fruit = mFruitList.get(position);
                Toast.makeText(v.getContext(), "you clicked view " + fruit.getName(), Toast.LENGTH_SHORT).showw();
            }
        });
        holder.fruitImage.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                int position = holder.getAdapterPosition();
                Fruit fruit = mFruitList.get(position);
                Toast.makeText(v.getContext(), "you clicked image " + fruit.getName(), Toast.LENGTH_SHORT).showw();
            }
        })
        return holder;
    }
    
    //對RecyclerView子項的資料進行賦值的,會在每個子項被滾動到螢幕內的時候執行
    @Override
    public void onBindViewHolder(ViewHolder holder, int position){
        Fruit fruit = mFruitList.get(position);
        holder.fruitImage.setImageResource(fruit.getImageId());
        holder.fruitName.setText(fruit.getName());
    }
    
    @Override
    public int getItemCount(){
        return mFruitList.size();
    }
}
  1. MainActivity:
public class MainActivity extends AppCompatAcitivy{
    private List<Fruit> fruitList = new ArrayList<>();
    
    @Override
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(sacedInstanceState);
        setContentView(R.layout.activity_main);
        
        initFruits();//初始化fruitList資料。方法略
        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        
        //LinearLayoutManager是線性佈局的意思,可以實現和ListView類似的效果。
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
        
        FruitAdapter adapter = new FruitAdapter(fruitList);
        recyclerView.setAdatper(adapter);
    }
}