[移动开发]RecyclerView的使用

RecyclerView

创建步骤：

1. 创建activity，顺便创建.xml文件，将recyclerView控件加入到.xml文件中去

   在XXXActivity文件的onCreate(Bundle savedInstanceState)中进行编写

   1. 通过 findViewById找到控件

   //获取RecyclerView对象
    mRecyclerView = findViewById(R.id.hole_rv);
   

   2. 配置layoutManager

   //设置layoutManager
   LinearLayoutManager layoutManager = new LinearLayoutManager(HoleActivity.this);
   mRecyclerView.setLayoutManager(layoutManager);
   

   3. 配置adapter(并编写java类)

   //设置adapter
   mMyAdapter = new HoleAdapter(HoleActivity.this, post_list);
   mRecyclerView.setAdapter(mMyAdapter);
   

   4. 设置Decoration分割线

   //设置Decoration分割线
   DividerItemDecoration decoration = new DividerItemDecoration(this, DividerItemDecoration.VERTICAL);
   decoration.setDrawable(getResources().getDrawable(R.drawable.divider, null));
   mRecyclerView.addItemDecoration(decoration);
   

2. 编写adapter类文件

   创建myAdapter文件并进行编写

   1. 首先extends RecyclerView.Adapter<ViewHolder>

   2. 编写构造函数(一般需要语境context以及数据list)

      public HoleAdapter(Context hole_context, List<post> list) {
          context = hole_context;
          post_list = list;
      }
      

   3. 再编写自己的myHolderr类，用来获取item对象(需要先创建item_XXX.xml文件)

      /**
       * @Description: 创建自己的Holder, 获取item对象
       * @Param:
       * @return:
       * @Author: YAO
       * @Date: 2022/3/5
       */
      public class myHolder extends RecyclerView.ViewHolder {
          TextView post_text;
      
          public myHolder(@NonNull View itemView) {
              super(itemView);
              post_text = itemView.findViewById(R.id.item_tv);
          }
      }
      

   4. 将RecyclerView.Adapter<ViewHolder> 改为RecyclerView.Adapter<myAdapter.myHolder>

   5. 重写函数onCreateViewHolder()(绑定item视图)

      /**
       * @Description: 绑定item视图
       * @Param: [parent, viewType]
       * @return: com.example.xkkh.adapter.HoleAdapter.myHolder
       * @Author: YAO
       * @Date: 2022/3/5
       */
      @NonNull
      @Override
      public myHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
          View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_hole, parent, false);
          myHolder myHolder = new myHolder(view);
          return myHolder;
      } 
      

   6. 重写函数onBindViewHolder()(绑定item数据)

      /**
       * @Description: 绑定item数据
       * @Param: [holder, position]
       * @return: void
       * @Author: YAO
       * @Date: 2022/3/5
       */
      @Override
      public void onBindViewHolder(@NonNull myHolder holder, int position) {
          post post = post_list.get(position);
          holder.post_text.setText(post.post_context);
      }
      

   7. 重写函数getItemCount()(返回item个数)

      /**
       * @Description: 返回item数量
       * @Param: []
       * @return: int
       * @Author: YAO
       * @Date: 2022/3/5
       */
      @Override
      public int getItemCount() {
          return post_list.size();
      }
      

      至此Recycler的设置完成