[移动开发]Android开发----RecyclerView

RecyclerView

一个用于大量数据展示的新控件,用来代替ListView

依赖

使用前需要导入依赖

//添加recyclerView依赖包
    implementation 'androidx.recyclerview:recyclerview:1.1.0'

实例练习

activity_main.xml

<?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="match_parent"
        android:orientation="vertical"
>
<androidx.recyclerview.widget.RecyclerView
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:id="@+id/rv"
          android:textSize="30sp"/>

</LinearLayout>

创建一个recyclerview_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
        android:layout_height="match_parent"
        android:layout_width="match_parent"
        android:orientation="vertical"
        xmlns:android="http://schemas.android.com/apk/res/android">
    <TextView    android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:id="@+id/tv"
              android:textSize="30sp"
    />
</LinearLayout>

创建两个类
Bean

package com.example.mylistview;

public class Bean {
    String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

MyAdapter
该类中每个方法有着相应的注释
并且在此类中绑定了项点击事件

package com.example.myrecyclerview;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import java.util.List;

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.myviewHolder>{
    private List<Bean> data;
    private Context context;

    public MyAdapter(List<Bean> data, Context context) {
        this.data = data;
        this.context = context;
    }

    @NonNull
    @Override
    public myviewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view=View.inflate(context,R.layout.recyclerview_item,null);
        return new myviewHolder(view);
    }
//    绑定数据
    @Override
    public void onBindViewHolder(@NonNull myviewHolder holder, int position) {
            holder.tv.setText(data.get(position).getName());
    }
    //显示的item长度
    @Override
    public int getItemCount() {
        return data==null ? 0 : data.size();
    }

    public class myviewHolder extends RecyclerView.ViewHolder{
        private TextView tv;
        public myviewHolder(@NonNull View itemView) {
            super(itemView);
            tv=itemView.findViewById(R.id.tv);
            //点击事件
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if(onitemClickListener!=null){
                        onitemClickListener.onRecyclerItemclick(getAdapterPosition());
                    }
                }
            });

        }
    }
    private  OnRecyclerItemClickListener onitemClickListener;
    public void setRecyclerItemClickListener(OnRecyclerItemClickListener onitemlistener){
        onitemClickListener=onitemlistener;
    }
    public interface OnRecyclerItemClickListener{
        void onRecyclerItemclick(int position);
    }
}

MainActivity

package com.example.myrecyclerview;

import android.util.Log;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.StaggeredGridLayoutManager;

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

public class MainActivity extends AppCompatActivity {
    private List<Bean> data=new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        for (int i=0;i<1000;i++){
            if(i%2!=0){
                continue;
            }
            Bean bean=new Bean();
            bean.setName("博客CSDN碰磕"+i);
            data.add(bean);
        }
        RecyclerView recyclerView=findViewById(R.id.rv);
        //线性布局
//        LinearLayoutManager linearLayoutManager=new LinearLayoutManager(this);
//        recyclerView.setLayoutManager(linearLayoutManager);
        //网格布局
//        GridLayoutManager gridLayoutManager=new GridLayoutManager(this,3);
//        recyclerView.setLayoutManager(gridLayoutManager);
        //瀑布流
        StaggeredGridLayoutManager staggeredGridLayoutManager=new StaggeredGridLayoutManager(2,StaggeredGridLayoutManager.VERTICAL);
        recyclerView.setLayoutManager(staggeredGridLayoutManager);

        MyAdapter adapter=new MyAdapter(data,this);
        recyclerView.setAdapter(adapter);
        adapter.setRecyclerItemClickListener(new MyAdapter.OnRecyclerItemClickListener() {
            @Override
            public void onRecyclerItemclick(int position) {
                Log.e("CSDN", "点击成功" + position);
            }
        });
    }
}

RecyclerView可作多个布局显示,此处练习了
线性布局,网格布局,
最后以瀑布流结尾
最终实例效果:

item点击事件触发效果: