本文目录

RecyclerView概述RecyclerView使用-基础篇第一步：添加RecyclerView第二步：添加布局文件第三步：添加逻辑代码运行效果

RecyclerView使用-进阶篇布局管理器线性布局管理器网格布局管理器

ItemDecorationItem 动画Item 点击

RecyclerView使用-高级篇（上拉刷新下拉加载更多）第一步：添加依赖第二步：布局文件第三步：逻辑代码完整代码

RecyclerView概述

RecyclerView是官方在5.0之后新添加的控件，推出用来替代传统的ListView和GridView列表控件。

RecyclerView使用-基础篇

第一步：添加RecyclerView

**方法1：**点开任意一个布局文件，找到左边的RecyclerView控件，点击旁边的按钮即可添加RecyclerView。 **方法2：**在build.gradle文件中添加依赖

implementation 'androidx.recyclerview:recyclerview:1.1.0'

第二步：添加布局文件

在布局文件activity_main.xml中先添加RecyclerView控件

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:id="@+id/recyclerview"

android:layout_width="match_parent"

android:layout_height="match_parent"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintLeft_toLeftOf="parent"

app:layout_constraintRight_toRightOf="parent"

app:layout_constraintTop_toTopOf="parent" />

再添加一个item_list.xml的布局文件

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">

android:id="@+id/textView"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_marginStart="29dp"

android:layout_marginTop="33dp"

android:text="标题"

app:layout_constraintStart_toStartOf="parent"

app:layout_constraintTop_toTopOf="parent" />

android:id="@+id/textView2"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_marginStart="4dp"

android:layout_marginTop="18dp"

android:text="内容"

app:layout_constraintStart_toStartOf="@+id/textView"

app:layout_constraintTop_toBottomOf="@+id/textView" />

第三步：添加逻辑代码

首先定一个实体类如下：

public class News {

public String title; // 标题

public String content; //内容

}

然后在MainActivity中定义内部类 ViewHolder类、 MyAdapter类以及设置RecyclerView相关逻辑

package com.lucashu.recyclerview;

import androidx.annotation.NonNull;

import androidx.appcompat.app.AppCompatActivity;

import androidx.recyclerview.widget.LinearLayoutManager;

import androidx.recyclerview.widget.RecyclerView;

import android.os.Bundle;

import android.view.View;

import android.view.ViewGroup;

import android.widget.TextView;

import java.util.ArrayList;

import java.util.List;

public class MainActivity extends AppCompatActivity {

RecyclerView mRecyclerView;

MyAdapter mMyAdapter ;

List mNewsList = new ArrayList<>();

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mRecyclerView = findViewById(R.id.recyclerview);

// 构造一些数据

for (int i = 0; i < 50; i++) {

News news = new News();

news.title = "标题" + i;

news.content = "内容" + i;

mNewsList.add(news);

}

mMyAdapter = new MyAdapter();

mRecyclerView.setAdapter(mMyAdapter);

LinearLayoutManager layoutManager = new LinearLayoutManager(MainActivity.this);

mRecyclerView.setLayoutManager(layoutManager);

}

class MyAdapter extends RecyclerView.Adapter {

@NonNull

@Override

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

View view = View.inflate(MainActivity.this, R.layout.item_list, null);

MyViewHoder myViewHoder = new MyViewHoder(view);

return myViewHoder;

}

@Override

public void onBindViewHolder(@NonNull MyViewHoder holder, int position) {

News news = mNewsList.get(position);

holder.mTitleTv.setText(news.title);

holder.mTitleContent.setText(news.content);

}

@Override

public int getItemCount() {

return mNewsList.size();

}

}

class MyViewHoder extends RecyclerView.ViewHolder {

TextView mTitleTv;

TextView mTitleContent;

public MyViewHoder(@NonNull View itemView) {

super(itemView);

mTitleTv = itemView.findViewById(R.id.textView);

mTitleContent = itemView.findViewById(R.id.textView2);

}

}

}

运行效果

RecyclerView使用-进阶篇

布局管理器

RecyclerView提供了三种布局管理器即：

LinearLayoutManager 线性布局管理器StaggeredGridLayoutManager 瀑布流布局管理器GridLayoutManager 网格布局管理器

线性布局管理器

这三种布局管理器都是通过setLayoutManager方法来设置 LinearLayoutManager 还可以设置横向滚动，只需将前面MainActivity中的layoutManager加一句代码即可：

LinearLayoutManager layoutManager = new LinearLayoutManager(MainActivity.this);

layoutManager.setOrientation(RecyclerView.HORIZONTAL);

mRecyclerView.setLayoutManager(layoutManager);

网格布局管理器

如果让一行显示多个，可以设置 GridLayoutManager网格布局管理器来实现

GridLayoutManager layoutManager = new GridLayoutManager(MainActivity.this,3);

// layoutManager.setOrientation(RecyclerView.HORIZONTAL); 也能设置横向滚动

mRecyclerView.setLayoutManager(layoutManager);

ItemDecoration

通过给 设置ItemDecoration 来装饰Item的效果，比如我们要设置间隔线

DividerItemDecoration mDivider = new

DividerItemDecoration(this,DividerItemDecoration.VERTICAL);

mRecyclerView.addItemDecoration(mDivider);

Item 动画

RecyclerView提供了默认的ItemAnimator实现类：DefaultItemAnimator。该类可以帮我们实现一些炫酷的动画效果

DefaultItemAnimator itemAnimator = new DefaultItemAnimator();

defaultItemAnimator.setAddDuration(1000);

defaultItemAnimator.setRemoveDuration(1000);

mRecyclerView.setItemAnimator(itemAnimator);

在MainActivity中添加了两个按钮， 一个添加item，一个删除item

Button button = findViewById(R.id.button);

button.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

News news = new News();

news.title = "标题 新内容" ;

news.content = "内容 新内容" ;

mNewsList.add(1,news);

mMyAdapter.notifyItemInserted(1);

}

});

Button button1 = findViewById(R.id.button1);

button1.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

mNewsList.remove(0);

mMyAdapter.notifyItemMoved(0,1);

}

});

效果如下：

Item 点击

可以通过对整个Item文件的根布局添加一个点击事件来实现Item的点击

效果如下：

RecyclerView使用-高级篇（上拉刷新下拉加载更多）

通常RecyclerView使用的时候需要配合上拉刷新下拉加载更多的功能 我们通过开源控件SmartRefreshLayout来实现 SmartRefreshLayout官网：https://github.com/scwang90/SmartRefreshLayout 使用方法如下：

第一步：添加依赖

在gradle文件中添加

implementation 'com.scwang.smartrefresh:SmartRefreshLayout:1.1.2'

implementation 'com.scwang.smartrefresh:SmartRefreshHeader:1.1.2'

第二步：布局文件

在activity_main.xml中SmartRefreshLayout控件将RecyclerView包裹起来

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:id="@+id/refreshLayout"

android:layout_width="match_parent"

android:layout_height="match_parent"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintTop_toTopOf="parent">

android:id="@+id/recyclerview"

android:layout_width="match_parent"

android:layout_height="0dp"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintLeft_toLeftOf="parent"

app:layout_constraintRight_toRightOf="parent"

app:layout_constraintTop_toTopOf="parent" />

第三步：逻辑代码

在MainActivity的onCreate方法中添加下拉刷新和上拉加载更多的功能

下拉刷新：

RefreshLayout refreshLayout = findViewById(R.id.refreshLayout);

refreshLayout.setOnRefreshListener(new OnRefreshListener() {

@Override

public void onRefresh(RefreshLayout refreshlayout) {

refreshlayout.finishRefresh(2000/*,false*/);//传入false表示刷新失败

mNewsList.clear();

for (int i = 0; i < 10; i++) {

News news = new News();

news.title = "标题 新内容" + i;

news.content = "内容" + i;

mNewsList.add(news);

}

mMyAdapter.notifyDataSetChanged();

}

});

上拉加载更多

refreshLayout.setOnLoadMoreListener(new OnLoadMoreListener() {

@Override

public void onLoadMore(RefreshLayout refreshlayout) {

refreshlayout.finishLoadMore(2000/*,false*/);//传入false表示加载失败

for (int i = 0; i < 10; i++) {

News news = new News();

news.title = "标题 新内容" + i;

news.content = "内容" + i;

mNewsList.add(news);

}

mMyAdapter.notifyDataSetChanged();

}

});

效果如下：

完整代码

MainActivity.java文件

package com.lucashu.recyclerview;

import androidx.annotation.NonNull;

import androidx.appcompat.app.AppCompatActivity;

import androidx.constraintlayout.widget.ConstraintLayout;

import androidx.recyclerview.widget.LinearLayoutManager;

import androidx.recyclerview.widget.RecyclerView;

import android.os.Bundle;

import android.view.View;

import android.view.ViewGroup;

import android.widget.TextView;

import android.widget.Toast;

import com.scwang.smartrefresh.layout.api.RefreshLayout;

import com.scwang.smartrefresh.layout.listener.OnLoadMoreListener;

import com.scwang.smartrefresh.layout.listener.OnRefreshListener;

import java.util.ArrayList;

import java.util.List;

public class MainActivity extends AppCompatActivity {

RecyclerView mRecyclerView;

MyAdapter mMyAdapter ;

List mNewsList = new ArrayList<>();

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mRecyclerView = findViewById(R.id.recyclerview);

// 构造一些数据

for (int i = 0; i < 10; i++) {

News news = new News();

news.title = "标题" + i;

news.content = "内容" + i;

mNewsList.add(news);

}

mMyAdapter = new MyAdapter();

mRecyclerView.setAdapter(mMyAdapter);

LinearLayoutManager layoutManager = new LinearLayoutManager(MainActivity.this);

mRecyclerView.setLayoutManager(layoutManager);

RefreshLayout refreshLayout = findViewById(R.id.refreshLayout);

refreshLayout.setOnRefreshListener(new OnRefreshListener() {

@Override

public void onRefresh(RefreshLayout refreshlayout) {

refreshlayout.finishRefresh(2000/*,false*/);//传入false表示刷新失败

mNewsList.clear();

for (int i = 0; i < 10; i++) {

News news = new News();

news.title = "标题 新内容" + i;

news.content = "内容" + i;

mNewsList.add(news);

}

mMyAdapter.notifyDataSetChanged();

}

});

refreshLayout.setOnLoadMoreListener(new OnLoadMoreListener() {

@Override

public void onLoadMore(RefreshLayout refreshlayout) {

refreshlayout.finishLoadMore(2000/*,false*/);//传入false表示加载失败

for (int i = 0; i < 10; i++) {

News news = new News();

news.title = "标题 新内容" + i;

news.content = "内容" + i;

mNewsList.add(news);

}

mMyAdapter.notifyDataSetChanged();

}

});

}

class MyAdapter extends RecyclerView.Adapter {

@NonNull

@Override

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

View view = View.inflate(MainActivity.this, R.layout.item_list, null);

MyViewHoder myViewHoder = new MyViewHoder(view);

return myViewHoder;

}

@Override

public void onBindViewHolder(@NonNull MyViewHoder holder, final int position) {

News news = mNewsList.get(position);

holder.mTitleTv.setText(news.title);

holder.mTitleContent.setText(news.content);

holder.mRootView.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

Toast.makeText(MainActivity.this,"点击了："+ position,Toast.LENGTH_LONG).show();

}

});

}

@Override

public int getItemCount() {

return mNewsList.size();

}

}

class MyViewHoder extends RecyclerView.ViewHolder {

TextView mTitleTv;

TextView mTitleContent;

ConstraintLayout mRootView;

public MyViewHoder(@NonNull View itemView) {

super(itemView);

mTitleTv = itemView.findViewById(R.id.textView);

mTitleContent = itemView.findViewById(R.id.textView2);

mRootView = itemView.findViewById(R.id.rootview);

}

}

}

activity_main.xml文件

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:id="@+id/refreshLayout"

android:layout_width="match_parent"

android:layout_height="match_parent"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintTop_toTopOf="parent">

android:id="@+id/recyclerview"

android:layout_width="match_parent"

android:layout_height="match_parent" />