RecyclerView横向(左右)滑动，item选中（单选）效果。

之前有小伙伴在群里问RecyclerView左右滑动单选效果怎么实现，左右滑动很简单，recyclerview自带属性支持，但是item单选让大家好像蒙圈了，有的人说写一个属性值来统计选中的item，list一大堆到时候控制很麻烦，我的思路很简单就是定义一个外部变量用来存储当前item选中的对象，item不就是一个view吗，那就定义一个view对象呗。点击item的时候先去判断view是否为空，如果不为空就把view改变成非选中状态，然后把点击的当前item改变成选中状态，把item对象赋值给view。就这么简单。（案例为了简单方便用的TextView改变颜色）https://github.com/renwavewave/RecyclerViewDemo（代码没传上去还是咋回事  各位抱歉了 代码先展示出来吧。地址已经更新可以下载了抱歉）

package com.example.wavewave.recyclerviewdemonew;

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.LinkedList;

public class TextAdapter extends RecyclerView.Adapter<TextAdapter.TextViewHolder> {
    private LinkedList<String> list;
    private TextView textView;
    private int oldPosition = 0;

    public TextAdapter(LinkedList<String> list) {
        this.list = list;
    }

    @NonNull
    @Override
    public TextViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        return new TextViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.my_item, parent, false));
    }

    @Override
    public void onBindViewHolder(@NonNull final TextViewHolder holder, final int position) {
        holder.textView.setText(list.get(position) + "");
        if (position == oldPosition) {
            textView = holder.textView;
            holder.textView.setTextColor(Color.parseColor("#FF4081"));
        } else {
            holder.textView.setTextColor(Color.parseColor("#000000"));
        }
        holder.textView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (textView != null) {
                    textView.setTextColor(Color.parseColor("#000000"));
                }
                holder.textView.setTextColor(Color.parseColor("#FF4081"));
                textView = holder.textView;
                oldPosition = position;
            }
        });
    }

    @Override
    public int getItemCount() {
        return list == null ? 0 : list.size();
    }

    class TextViewHolder extends RecyclerView.ViewHolder {
        TextView textView;

        public TextViewHolder(View itemView) {
            super(itemView);
            textView = itemView.findViewById(R.id.textView);
        }
    }
}

package com.example.wavewave.recyclerviewdemo;


import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

import java.util.LinkedList;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        LinkedList<String> linkedList = new LinkedList();
        for (int i = 0; i < 20; i++)
            linkedList.add("小明" + i + "号");
        RecyclerView recyclerView = findViewById(R.id.recyclerView);
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
        //配置布局，默认为vertical（垂直布局），下边这句将布局改为水平布局
        linearLayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.setAdapter(new TextAdapter(linkedList));

    }
}

xml

<android.support.v7.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

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

my_item

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/textView"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:gravity="center"
        android:text="选中"
        android:textColor="#000000" />
</RelativeLayout>