RecyclerView的用法

1.增加依赖库

2.activity_ main.xml 文件 

  

 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:id="@+id/activity_main"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.sh.recyclerviewtest.MainActivity">


    <!--RecyclerView 并不是内置在系统sdk当中的，所以需要把完整的路径写出来-->
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="vertical"
        >

    </android.support.v7.widget.RecyclerView>
</LinearLayout>

3.定义实体类 Fruit.class

public class Fruit {
    private String name;
    private int imageId;

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

4.fruit_item.xml  定义listview子项的自定义布局文件 

<?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="vertical"
              android:layout_margin="5dp"
              >

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


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

    5.FruitAdapter.class 定义一个适配器 

    

public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder>{
    private List<Fruit> mFruitList;
    static  class ViewHolder extends  RecyclerView.ViewHolder{
        View fruitView;
        ImageView fruitImageId;
        TextView fruitName;
        public ViewHolder(View view)
        {
            super(view);
            fruitView = view;
            fruitImageId = (ImageView)view.findViewById(R.id.fruit_image);
            fruitName = (TextView) view.findViewById(R.id.fruit_name);
        }
    }

    public FruitAdapter(List<Fruit> fruitList)
    {
        mFruitList = fruitList;
    }

    @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 positiion = holder.getAdapterPosition();
                    Fruit fruit = mFruitList.get(positiion);
                 Toast.makeText(v.getContext(), "you clicked view"+ fruit.getName(), Toast.LENGTH_SHORT).show();
             }
         });
        holder.fruitImageId.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int positiion = holder.getAdapterPosition();
                Fruit fruit = mFruitList.get(positiion);
                Toast.makeText(v.getContext(), "you clicked image"+ fruit.getName(), Toast.LENGTH_SHORT).show();
            }
        });
        return holder;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        Fruit fruit = mFruitList.get(position);
        holder.fruitImageId.setImageResource(fruit.getImageId());
        holder.fruitName.setText(fruit.getName());
    }

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

6.MainActivity.java

  
public class MainActivity extends AppCompatActivity {
    private List<Fruit> fruitList = new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       initFruits(); //初始华水果数据
        RecyclerView recyclerView = (RecyclerView)findViewById(R.id.recycler_view);
       // LinearLayoutManager layoutManager =new LinearLayoutManager(this);
        //LinearLayoutManager layoutManager =new GridLayoutManager(this);

     //   LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL);
        //3.给linearLayoutManager设置滑动的方向
//        layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
        //4.为recyclerView设置布局管理器
        recyclerView.setLayoutManager(layoutManager);


//        recyclerView.setLayoutManager(layoutManager);
        FruitAdapter adapter =  new FruitAdapter(fruitList);
        recyclerView.setAdapter(adapter);
    }
    public  void initFruits()
    {
        for (int i =0;i< 4 ; i ++ ){
            Fruit apple =  new Fruit(getRamdonLengthName("apple"),R.drawable.apple);
            fruitList.add(apple);

            Fruit banana =  new Fruit(getRamdonLengthName("banana"),R.drawable.banana);
            fruitList.add(banana);

            Fruit orange =  new Fruit(getRamdonLengthName("orange"),R.drawable.orange);
            fruitList.add(orange);

            Fruit pear =  new Fruit(getRamdonLengthName("pear"),R.drawable.pear);
            fruitList.add(pear);
            Fruit watermelon =  new Fruit(getRamdonLengthName("watermelon"),R.drawable.watermelon);
            fruitList.add(watermelon);
        }
    }

     private String getRamdonLengthName(String name)
     {
         Random random = new Random();
         int length = random.nextInt(20)+1;
         StringBuilder builder = new StringBuilder();
         for (int i=0;i<length;i++)
         {
             builder.append(name);
         }
         return builder.toString();
     }
}