Android 下拉刷新上啦加载SmartRefreshLayout + RecyclerView

在弄android刷新的时候，可算是耗费了一番功夫，最后发觉有现成的控件，并且非常好用，这里记录一下。

原文是 https://blog.csdn.net/huangxin112/article/details/78781682 ，这里是看了之后，结合自己实际遇到的问题写的。

首先引入包。

    //下拉框
    implementation 'com.android.support:recyclerview-v7:28.0.0-beta01'
    implementation 'com.scwang.smartrefresh:SmartRefreshLayout:1.0.3'
    implementation 'com.scwang.smartrefresh:SmartRefreshHeader:1.0.3'//没有使用特殊Header，可以不加这行

recyclerview 是为了数据显示用，因为在使用中，发现 使用ListView 会报错，不过我看别人用成功了的，具体我也懒得去查了。

recyclerview 以后具体在学习吧，反正是个比较好用的东西就是了。
首先是页面文件 activity_main.xml

<com.scwang.smartrefresh.layout.SmartRefreshLayout
    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:id="@+id/refreshLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
    >
<android.support.v7.widget.RecyclerView
    android:id="@+id/recyclerview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:overScrollMode="never"
    android:background="#fff" />

</com.scwang.smartrefresh.layout.SmartRefreshLayout>

接着是具体的布局显示文件： item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="60dp"
    android:gravity="center">

    <ImageView
        android:id="@+id/iv_image"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:gravity="center"
        android:background="@mipmap/ic_launcher"></ImageView>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <TextView
            android:id="@+id/tv_title"
            android:layout_width="match_parent"
            android:layout_height="30dp"
            android:text="title"
            android:gravity="center"
            ></TextView>

        <TextView
            android:id="@+id/tv_content"
            android:layout_width="match_parent"
            android:layout_height="30dp"
            android:text="content1231231231232323"
            android:gravity="center"
            ></TextView>
    </LinearLayout>

</LinearLayout>

显示的bean 对象，

package com.example.administrator.shuaxin;

public class ItemBean {
    int itemImage;
    String itemTitle;
    String itemContent;

    public ItemBean(int itemImage , String itemTitle, String itemContent) {
        this.itemTitle = itemTitle;
        this.itemContent = itemContent;
        this.itemImage = itemImage;
    }

}

适配器MyAdapter：

package com.example.administrator.shuaxin;

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.List;

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder>{
    private List<ItemBean> mList;

    static class ViewHolder extends RecyclerView.ViewHolder{
        View myView;
        ImageView imageView;
        TextView title;
        TextView content;
        public ViewHolder(View itemView) {
            super(itemView);
            myView = itemView;
            imageView = (ImageView) itemView.findViewById(R.id.iv_image);
            title = (TextView) itemView.findViewById(R.id.tv_title);
            content = (TextView) itemView.findViewById(R.id.tv_content);
        }
    }

    public MyAdapter(List<ItemBean> list){
        this.mList = list;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item,null);
        final ViewHolder holder = new ViewHolder(view);
        return holder;
    }

    //将数据绑定到控件上
    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        ItemBean bean = mList.get(position);
        holder.imageView.setBackgroundResource(bean.itemImage);
        holder.title.setText(bean.itemTitle);
        holder.content.setText(bean.itemContent);
    }

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

    //下面两个方法提供给页面刷新和加载时调用
    public void add(List<ItemBean> addMessageList) {
        //增加数据
        int position = mList.size();
        mList.addAll(position, addMessageList);
        notifyItemInserted(position);
    }

    public void refresh(List<ItemBean> newList) {
        //刷新数据
        mList.removeAll(mList);
        mList.addAll(newList);
        notifyDataSetChanged();
    }
}

然后是Activity文件。

 package com.example.administrator.shuaxin;

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

import com.scwang.smartrefresh.header.MaterialHeader;
import com.scwang.smartrefresh.layout.api.RefreshLayout;
import com.scwang.smartrefresh.layout.footer.ClassicsFooter;
import com.scwang.smartrefresh.layout.header.ClassicsHeader;
import com.scwang.smartrefresh.layout.listener.OnLoadmoreListener;
import com.scwang.smartrefresh.layout.listener.OnRefreshListener;

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

 public class MainActivity extends AppCompatActivity {

     private List<ItemBean> list;
     private MyAdapter myAdapter;
     private RecyclerView recyclerView;
     RefreshLayout refreshLayout;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         refreshLayout = (RefreshLayout)findViewById(R.id.refreshLayout);
         //初始数据加载
         initDate();
         //刷新数据加载
         setPullRefresher();
     }

     private void initDate(){
         list = new ArrayList<ItemBean>();
         for (int i=0;i<20;i++){
             list.add(new ItemBean(
                     R.mipmap.ic_launcher,
                     "initTitle"+i,
                     new Date().toString()+""
             ));
         }
         myAdapter = new MyAdapter(list);
         recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
         LinearLayoutManager layoutManager = new LinearLayoutManager(this);//纵向线性布局

         recyclerView.setLayoutManager(layoutManager);
         recyclerView.setAdapter(myAdapter);
     }

     private void setPullRefresher(){
         //设置 Header 为 MaterialHeader
         //设置 Header 为 ClassicsFooter 比较经典的样式
         refreshLayout.setRefreshHeader(new ClassicsHeader(this));
         //设置 Footer 为 经典样式
         refreshLayout.setRefreshFooter(new ClassicsFooter(this));

         refreshLayout.setOnRefreshListener(new OnRefreshListener() {
             @Override
             public void onRefresh(RefreshLayout refreshlayout) {
                 //在这里执行上拉刷新时的具体操作(网络请求、更新UI等)

                 //模拟网络请求到的数据
                 ArrayList<ItemBean> newList = new ArrayList<ItemBean>();
                 for (int i=0;i<20;i++){
                     newList.add(new ItemBean(
                             R.mipmap.ic_launcher,
                             "newTitle"+i,
                             new Date().toString()+""
                     ));
                 }
                 myAdapter.refresh(newList);
                 refreshlayout.finishRefresh(2000/*,false*/);
                 //不传时间则立即停止刷新    传入false表示刷新失败
             }
         });
         refreshLayout.setOnLoadmoreListener(new OnLoadmoreListener() {
             @Override
             public void onLoadmore(RefreshLayout refreshlayout) {

                 //模拟网络请求到的数据
                 ArrayList<ItemBean> newList = new ArrayList<ItemBean>();
                 for (int i=0;i<20;i++){
                     newList.add(new ItemBean(
                             R.mipmap.ic_launcher,
                             "addTitle"+i,
                             new Date().toString()+""
                     ));
                 }
                 myAdapter.add(newList);
                 //在这里执行下拉加载时的具体操作(网络请求、更新UI等)
                 refreshlayout.finishLoadmore(2000/*,false*/);//不传时间则立即停止刷新    传入false表示加载失败
             }
         });
     }

 }

看下效果。