RecycleView最简教程

阳光穿透心脏的1/2处 2022-05-25 03:12 212阅读 0赞

# RecyclerView详解 #

这可能是RecyclerView最简单的入门程序了，本篇文章只适合Recycle入门，请轻喷

## RecycleView介绍 ##

RecycleView可以用来替代ListView以及GridView可以自定义炫酷的效果。在使用RecycleView的过程中需要了解一下四点

*  LayoutManager布局管理器控制每一个item的布局方式
 *  ItemAnimator每一个Item增加与删除的动画效果
 *  ItemDecoration Item之间的间隔控制
 *  item点击事件，自己写，莫名喜感，哈哈哈哈哈

# 如果没有耐心，请直接下载代码，没有代码的教程都是耍流氓！！！ #

[demo地址][demo]

# 入门阶段 #

## 在工程中引入RecycleView ##

implementation 'com.android.support:recyclerview-v7:27.1.0'

## 在MainActivity布局文件main\_activity中引入 RecyclerView ##

<?xml version="1.0" encoding="utf-8"?>
    <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">
    
       <android.support.v7.widget.RecyclerView
           android:id="@+id/main_activity_recycleview"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           >
       </android.support.v7.widget.RecyclerView>
    
    </android.support.constraint.ConstraintLayout>

## 新建Adapter将要加载的布局文件item\_recycle\_view ##

<?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="horizontal" android:layout_margin="10dp" >
        <ImageView android:id="@+id/item_pic_iv" android:layout_width="120dp" android:layout_height="100dp" android:background="@mipmap/scene1" />
    
        <TextView android:id="@+id/item_name_tv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:gravity="right" android:layout_weight="1" android:text="点击" />
    
    </LinearLayout>

## 新建RecycleViewAdapter ##

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder>{ 
    
        private int[] pics;
        private String[] names;
    
    
        public RecyclerViewAdapter(int[] pics,String[] names){
            this.pics=pics;
            this.names=names;
        }
    
    
        @NonNull
        @Override
        public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            //使用此方法将不能适配父组件的布局
            // View view=View.inflate(parent.getContext(),R.layout.item_recycle_view,null);
            View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.item_recycle_view,parent,false);
            ViewHolder viewHolder=new ViewHolder(view);
            return viewHolder;
        }
    
        //用于绑定数据
        @Override
        public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
            holder.imageView.setBackgroundResource(pics[position]);
            holder.textView.setText(names[position]);
    
        }
    
        //返回的item总数
        @Override
        public int getItemCount() {
            return pics.length;
        }
    
        public static class ViewHolder extends RecyclerView.ViewHolder{ 
    
            private ImageView imageView;
    
            private TextView textView;
    
            public ViewHolder(View itemView) {
                super(itemView);
    
                imageView=(ImageView)itemView.findViewById(R.id.item_pic_iv);
                textView=(TextView)itemView.findViewById(R.id.item_name_tv);
            }
        }
    }

在MainActivity中加载RecycleView布局

public class MainActivity extends AppCompatActivity { 
    
        private RecyclerView recyclerView;
    
        private RecyclerViewAdapter recycleViewAdapter;
    
    
        private int[] pics;
    
        private String[] names;
    
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            initView();
        }
    
        private void initData(){
            pics=new int[]{R.mipmap.scene1,R.mipmap.scene01,R.mipmap.scene02,R.mipmap.scene03,R.mipmap.scene04};
            names=new String[]{
       "景点1","景点2","景点3","景点4","景点5"};
    
        }
    
        private void initView(){
    
            initData();
    
            recyclerView=(RecyclerView)findViewById(R.id.main_activity_recycleview);
    
            recyclerView.setLayoutManager(new LinearLayoutManager(this));
    
            recycleViewAdapter=new RecyclerViewAdapter(pics,names);
    
            recyclerView.setAdapter(recycleViewAdapter);
    
    
        }
    
    }

运行结果：假装这里有图片  
Demo地址

# 为Item添加点击事件阶段 #

因为RecyclerView自身没有点击事件的方法，因此需要自己编写点击事件。通过在Adapter中设置点击监听，并将接口暴露出来来实现。

基于以上的步骤，只需要修改RecyclerViewAdapter以及MainActivity中的代码即可

RecyclerViewAdapter中为每一个Item添加点击事件，同时将需要的点击事件的接口暴露给外部调用，直接贴代码

## 修改RecyclerAdapter中的代码 ##

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder>{
    
        private int[] pics;
        private String[] names;
    
        public OnItemClickListener onItemClickListener;
    
    
        public RecyclerViewAdapter(int[] pics,String[] names){
            this.pics=pics;
            this.names=names;
        }
    
    
        @NonNull
        @Override
        public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            //使用此方法将不能适配父组件的布局
            // View view=View.inflate(parent.getContext(),R.layout.item_recycle_view,null);
            View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.item_recycle_view,parent,false);
            ViewHolder viewHolder=new ViewHolder(view);
            return viewHolder;
        }
    
        //用于绑定数据
        @Override
        public void onBindViewHolder(@NonNull ViewHolder holder, final int position) {
            holder.imageView.setBackgroundResource(pics[position]);
            holder.textView.setText(names[position]);
    
            //为整个item添加点击事件
    // holder.itemView.setOnClickListener(new View.OnClickListener() { 
    // @Override
    // public void onClick(View v) { 
    // onItemClickListener.OnItemClickListener(position,names);
    // }
    // });
            //只为item中的某一个元素添加点击事件
            holder.textView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    onItemClickListener.OnItemClickListener(position,names);
                }
            });
    
        }
    
        //返回的item总数
        @Override
        public int getItemCount() {
            return pics.length;
        }
    
        public static class ViewHolder extends RecyclerView.ViewHolder{
    
            private ImageView imageView;
    
            private TextView textView;
    
            public ViewHolder(View itemView) {
                super(itemView);
    
                imageView=(ImageView)itemView.findViewById(R.id.item_pic_iv);
                textView=(TextView)itemView.findViewById(R.id.item_name_tv);
            }
        }
    
    
        /** * 当item被点击的时进行回调 * */
    
        public  interface OnItemClickListener{
            void OnItemClickListener(int pos,String[] names);
        }
    
    
        /** * 用于将每一次点击事件暴露到外面 * */
        public void setOnItemClickListener(OnItemClickListener onItemClickListener){
    
            this.onItemClickListener=onItemClickListener;
    
        }
    }

## 修改MainActivity中的代码 ##

public class MainActivity extends AppCompatActivity implements RecyclerViewAdapter.OnItemClickListener{ 
    
        private RecyclerView recyclerView;
    
        private RecyclerViewAdapter recycleViewAdapter;
    
    
        private int[] pics;
    
        private String[] names;
    
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            initView();
        }
    
        private void initData(){
            pics=new int[]{R.mipmap.scene1,R.mipmap.scene01,R.mipmap.scene02,R.mipmap.scene03,R.mipmap.scene04};
            names=new String[]{
       "景点1","景点2","景点3","景点4","景点5"};
    
        }
    
        private void initView(){
    
            initData();
    
            recyclerView=(RecyclerView)findViewById(R.id.main_activity_recycleview);
    
            recyclerView.setLayoutManager(new LinearLayoutManager(this));
    
            //网格布局
            //recyclerView.setLayoutManager(new GridLayoutManager(this,2));
    
    
            recycleViewAdapter=new RecyclerViewAdapter(pics,names);
    
            recycleViewAdapter.setOnItemClickListener(this);
    
            recyclerView.setAdapter(recycleViewAdapter);
    
    
        }
    
        @Override
        public void OnItemClickListener(int pos, String[] names) {
    
            Toast.makeText(this,names[pos],Toast.LENGTH_LONG).show();
    
        }
    }

[demo]: https://download.csdn.net/download/lrici/10397474