关于Recycler工具类的设计

 CommonRecyclerAdapter类

package com.example.example.util;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;

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

import java.util.List;
import java.util.Map;

public abstract  class CommonRecyclerAdapter<T> extends RecyclerView.Adapter<CommonViewHolder> {
    private List<T> dataList;
    private Map<String,Integer> idMap;
    private int itemLayout;
    private Context context;

    public CommonRecyclerAdapter(List<T> dataList, Map<String, Integer> idMap, int itemLayout, Context context) {
        this.dataList = dataList;
        this.idMap = idMap;
        this.itemLayout = itemLayout;
        this.context = context;
    }

    @NonNull
    @Override
    public CommonViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View embedView=View.inflate(context,itemLayout,null);
        return new CommonViewHolder(embedView,idMap);
    }

    @Override
    public void onBindViewHolder(@NonNull CommonViewHolder holder, int position) {
      T device=dataList.get(position);
      paddingCallback(device,holder);

    }

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

    public  abstract  void  paddingCallback(T t,CommonViewHolder holder);
}

CommonViewHolder类

package com.example.example.util;

import android.view.View;

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

import java.util.HashMap;
import java.util.Map;

public class CommonViewHolder  extends RecyclerView.ViewHolder {
    public Map<String, View> componentMap=new HashMap<>();


    public CommonViewHolder(@NonNull View itemView,Map<String,Integer> idMap) {
        super(itemView);
        for (Map.Entry<String,Integer> entry:idMap.entrySet()){
            componentMap.put(entry.getKey(),itemView.findViewById(entry.getValue()));
        }
    }
    public <T> T getView(String tag){
        return  (T)componentMap.get(tag);
    }
}

//主类的方法

private void createRecyclerView() {
  //获取父布局，layout里面设置的androidx.recyclerview.widget.RecyclerView

    RecyclerView recyclerView=findViewById(R.id.Recycler);
//创建一个map对象。用于存放item里面的控件，当前item里面只有两个控件，分别是TextView和ImageButton
    Map<String,Integer>  map=new HashMap<>();
//存入map容器中
    map.put("TV_DI_CONTEXT",R.id.tv_di_context);
    map.put("IB_DI_IMAGE",R.id.ib_di_image);
//给主布局设置适配器，传入四个参数，分别是数据的list对象，item存入map的控件，item的布局，以及当前类的context对象
    recyclerView.setAdapter(new CommonRecyclerAdapter<User>(list,map,R.layout.recycle_di,this) {
        @Override
        public void paddingCallback(User user, CommonViewHolder holder) {
//取出对象
            TextView textView=holder.getView("TV_DI_CONTEXT");
            ImageButton imageButton=holder.getView("IB_DI_IMAGE");
            textView.setText(user.getContext());
        }
    });
    recyclerView.setLayoutManager(new LinearLayoutManager(RecyclerTest.this));
}

item布局

 

 

主layout

 

 

 优化之后的运行界面