RecyclerView条目点击背景变色

这个问题一直困扰好多小伙伴,今天来给大家做一个超级简单的小demo来示范一下!

先口述一下思路,毕竟聪明的小伙伴不看代码也能理解!在适配器里设置接口回调并刷新适配器,再定义一个int的变量 设置set get方法,在界面调用接口

把点击的下标利用int变量的set方法传送回适配器,并刷新适配器.再设置数据的onBindViewHolder方法里进行下标的判断如果相同设置颜色,如果不同设置初始化颜色.这样一来也不必考虑条目复用的问题了 下面代码展示

适配器代码

package com.example.lenovo.itembackupdata;

import android.content.Context;


import android.graphics.Color;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import android.widget.TextView;

import java.util.ArrayList;
import java.util.HashMap;

/**
 * Created by lenovo on 2019/7/31.
 */

public class MyAdapter extends RecyclerView.Adapter {

    private ArrayList list;
    private Context context;
    private HashMap map;


    public MyAdapter(ArrayList list, Context context) {
        this.list = list;
        this.context = context;
    }

    @NonNull
    @Override
    public MyHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        View v = LayoutInflater.from(context).inflate(R.layout.layout_item, null);
        return new MyHolder(v);
    }

    @Override
    public void onBindViewHolder(@NonNull final MyHolder holder, final int position) {
        holder.tv.setText(list.get(position));
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
//                一定要刷新适配器 当条目发生改变这是必须的
                getListener.onClick(position);
                notifyDataSetChanged();

            }
        });
//        如果下标和传回来的下标相等 那么确定是点击的条目 把背景设置一下颜色
        if (position == getmPosition()) {
            holder.itemView.setBackgroundColor(Color.BLUE);
        }else{
//            否则的话就全白色初始化背景
            holder.itemView.setBackgroundColor(Color.WHITE);
        }
    }

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

    class MyHolder extends RecyclerView.ViewHolder {
        TextView tv;
        public MyHolder(View itemView) {
            super(itemView);

            tv = itemView.findViewById(R.id.tv_item);

        }
    }


    public interface GetListener {

        void onClick(int position);
    }

    private GetListener getListener;

    public void setGetListener(GetListener getListener) {
        this.getListener = getListener;
    }
    private  int mPosition;

    public int getmPosition() {
        return mPosition;
    }

    public void setmPosition(int mPosition) {
        this.mPosition = mPosition;
    }
}

界面代码:

package com.example.lenovo.itembackupdata;

import android.graphics.Color;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DividerItemDecoration;
import android.support.v7.widget.LinearLayoutManager;
import android.view.View;

import com.jcodecraeer.xrecyclerview.XRecyclerView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity  {

    private com.jcodecraeer.xrecyclerview.XRecyclerView recyc;

    private MyAdapter myAdapter;
    private ArrayList list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        this.recyc = (XRecyclerView) findViewById(R.id.recyc);

        init();

    }

    private void init() {
        recyc.setLayoutManager(new LinearLayoutManager(this));
        list = new ArrayList<>();
        for (int i = 0; i < 30; i++) {
         list.add("测试"+i);
        }
        myAdapter = new MyAdapter(list, this);
        recyc.setAdapter(myAdapter);
        recyc.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL));

        myAdapter.setGetListener(new MyAdapter.GetListener() {

            @Override
            public void onClick(int position) {
//                把点击的下标回传给适配器 确定下标
                myAdapter.setmPosition(position);
                myAdapter.notifyDataSetChanged();
            }
        });


    }


}

以上就是简单的点击变色,具体更多的逻辑需要各位小伙伴们匹配对应需求去增加逻辑代码即可!如果喜欢大家可以点点小红心 或者互相加关注一起研究一起学习