android中RecyclerView下拉刷新上拉加载更多

初次使用RecyclerView的时候踩了很多坑，比如数据造好了adapter写好了set之后不是没数据就是显示不全要么就是崩溃各种难受，后来总算数据显示了，就要考虑刷新以及加载更多的问题了。起初我也是想的像当年实现ListView的刷新和加载更多一样添加headerView和footview，后来到网上看了一下原来已经有别的方式了，不用那么麻烦。

一、下拉刷新

1、至于下拉刷新只需要在RecyclerView外嵌套SwipeRefreshLayout即可实现下拉刷新效果

<android.support.v4.widget.SwipeRefreshLayout

android:id="@+id/swip_live_pub"

android:layout_width="match_parent"

android:layout_height="match_parent">

<android.support.v7.widget.RecyclerView

android:id="@+id/recy_live_pub"

android:layout_width="match_parent"

android:layout_height="match_parent"/>

</android.support.v4.widget.SwipeRefreshLayout>

2、SwipeRefreshLayout可以设置setOnRefreshListener在刷新键听里面就可以做自己要刷新的请求了

switchRefreshLayout.setOnRefreshListener(newSwipeRefreshLayout.OnRefreshListener() {

@Override

public voidonRefresh() {

//TODO做自己刷新相关的业务

//switchRefreshLayout.setRefreshing(false);//用于结束页面刷新进度效果

}

});

二、上拉加载更多

1、其实RecyclerView的RecyclerView.Adapter也可以实现同一列表页面多种布局效果，那么这样就好办了，我们只需要给列表结尾添加一个item显示加载更多的样式即可,照着这个思路往下走，页面时可以实现了。但是出现的时机怎么监听，怎么知道最后一条出现了去执行加载更多的异步请求。我们可以用recyclerView.addOnScrollListener(...)监听recyclerView的滑动事件,在滑动的过程中我们可以通过mLinearLayoutManager.findLastVisibleItemPosition();获取到当前显示的最后一项item的position，当这个position恰好是最后一项时执行加载更多，就这样变便实现了上啦加载的需求业务。

2、实现上拉加载代码

LinearLayoutManagermLinearLayoutManager;

inttotalItemCount;

intlastVisibleItem;

intfirstVisibleItem;

recyclerView.addOnScrollListener(newRecyclerView.OnScrollListener() {

@Override

public voidonScrollStateChanged(RecyclerView recyclerView,intnewState) {

super.onScrollStateChanged(recyclerView, newState);

}

@Override

public voidonScrolled(RecyclerView recyclerView,intdx,intdy) {

super.onScrolled(recyclerView, dx, dy);

lastVisibleItem=mLinearLayoutManager.findLastVisibleItemPosition();

firstVisibleItem=mLinearLayoutManager.findFirstVisibleItemPosition();

totalItemCount=mLinearLayoutManager.getItemCount();

if(lastVisibleItem==totalItemCount-1&&firstVisibleItem!=0){

//TODO在此处执行自己加载更多数据的异步

}

}

});

三、针对这个下拉刷新和上啦加载我自己封装了一个BaseRecyclerAdapter，只要继承它便可实现，我把代码以及使用方式贴上欢迎使用和指正

1、这个是BaseRecyclerAdapter

public abstract classBaseRecyclerAdapterextendsRecyclerView.AdapterimplementsView.OnClickListener, View.OnLongClickListener {

protectedContextmContext;

protectedListdatas;//数据

protectedLayoutInflatermInflate;

protected final intTYPE_ITEM=0;

protected final intTYPE_FOOTER=1;

private final intPAGE_SIZE=20;

protected finalStringTAG=this.getClass().getName();

privateOnRecyclerViewItemClickListenermOnItemClickListener=null;

private booleanisFootView=false;//根据加载数据的情况，判断是否需要继续显示加载

private booleanisLoading=false;

private booleanloadOver=false;

private booleanisNeedFootView=false;//是否需要拉加载更多，true需要，false不需要

//自定义监听事件

public static interfaceOnRecyclerViewItemClickListener {

voidonItemClick(View view);

voidonItemLongClick(View view);

}

public voidsetOnItemClickListener(OnRecyclerViewItemClickListener listener) {

mOnItemClickListener= listener;

}

//适配器初始化

publicBaseRecyclerAdapter(Context context, List datas) {

mContext=context;

this.datas=datas;

setHasStableIds(true);

}

@Override

public intgetItemViewType(intposition) {

//判断item类别

if(position !=datas.size()) {

returnTYPE_ITEM;

}else{

returnTYPE_FOOTER;

}

}

publicList getList(){

returndatas;

}

public voidsetList(List datas){

this.datas= datas;

}

@Override

publicRecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent,intviewType) {

mInflate= LayoutInflater.from(mContext);

if(viewType !=TYPE_FOOTER){

returnonCreateItemViewHolder(parent, viewType);

}else{

View view =mInflate.inflate(R.layout.footer_load_view, parent,false);

return newFooterLoadHolder(view);

}

}

public abstractRecyclerView.ViewHolder onCreateItemViewHolder(ViewGroup parent,intviewType);

@Override

public voidonBindViewHolder(RecyclerView.ViewHolder holder,intposition) {

}

@Override

public intgetItemCount() {

if(isNeedFootView){

if(isFootView)returndatas.size() +1;//获取数据的个数

else returndatas.size();

}else returndatas.size();

}

@Override

public longgetItemId(intposition) {

returnposition;

}

//点击事件回调

@Override

public voidonClick(View v) {

if(mOnItemClickListener!=null) {

mOnItemClickListener.onItemClick(v);

}

}

@Override

public booleanonLongClick(View v) {

if(mOnItemClickListener!=null) {

mOnItemClickListener.onItemLongClick(v);

}

return false;

}

//自定义ViewHolder，用于显示footer

classFooterLoadHolderextendsRecyclerView.ViewHolder {

publicFooterLoadHolder(View itemView) {

super(itemView);

}

}

LinearLayoutManagermLinearLayoutManager;

inttotalItemCount;

intlastVisibleItem;

intfirstVisibleItem;

public final voidregisterRefreshAndLoadMoreListener(RecyclerView recyclerView,finalSwipeRefreshLayout switchRefreshLayout,finalPullListener pullListener){

mLinearLayoutManager=(LinearLayoutManager) recyclerView.getLayoutManager();

switchRefreshLayout.setOnRefreshListener(newSwipeRefreshLayout.OnRefreshListener() {

@Override

public voidonRefresh() {

pullListener.pullToRefresh(newRefreshAndLoadNotify() {

@Override

public voidrefreshNotify(List refreshList) {

if(refreshList ==null|| refreshList.size() ==0){

ToastUtil.showToast("已是最新一条");

switchRefreshLayout.setRefreshing(false);

return;

}

datas.removeAll(refreshList);

datas.addAll(0,refreshList);

lastVisibleItem=mLinearLayoutManager.findLastVisibleItemPosition();

notifyDataSetChanged();

switchRefreshLayout.setRefreshing(false);

}

@Override

public voidloadMoreNotify(List list) {

}

});

}

});

recyclerView.addOnScrollListener(newRecyclerView.OnScrollListener() {

@Override

public voidonScrollStateChanged(RecyclerView recyclerView,intnewState) {

super.onScrollStateChanged(recyclerView, newState);

}

@Override

public voidonScrolled(RecyclerView recyclerView,intdx,intdy) {

super.onScrolled(recyclerView, dx, dy);

lastVisibleItem=mLinearLayoutManager.findLastVisibleItemPosition();

firstVisibleItem=mLinearLayoutManager.findFirstVisibleItemPosition();

totalItemCount=mLinearLayoutManager.getItemCount();

if(lastVisibleItem

isFootView=true;

notifyDataSetChanged();

return;

}

LogUtil.log(TAG, Log.ERROR, (isFootView&&lastVisibleItem==totalItemCount-1&&firstVisibleItem!=0)+"=========isLoading====="+isLoading);

if(isFootView&&lastVisibleItem==totalItemCount-1&&firstVisibleItem!=0){

if(isLoading)return;

isLoading=true;

pullListener.pullToLoadMore(newRefreshAndLoadNotify() {

@Override

public voidrefreshNotify(List list) {

}

@Override

public voidloadMoreNotify(List moreLoadList) {

if(moreLoadList ==null|| moreLoadList.size() 

isFootView=false;

loadOver=true;

ToastUtil.showToast("已加载至最后一条");

}

if(moreLoadList !=null&& moreLoadList.size() >0){

datas.removeAll(moreLoadList);

datas.addAll(datas.size(), moreLoadList);

}

notifyDataSetChanged();

isLoading=false;

}

});

}

}

});

}

}

2、这个是footview

<?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="60dip"

android:background="@color/white"

android:orientation="horizontal">

<LinearLayout

android:layout_width="match_parent"

android:layout_height="30dip"

android:layout_gravity="center"

android:gravity="center"

android:layout_marginTop="5dip"

android:layout_marginBottom="5dip"

android:background="@color/white"

android:orientation="horizontal">

<ProgressBar

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:background="@color/white"/>

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_marginLeft="5dip"

android:text="加载中..."/>

</LinearLayout>

</LinearLayout>

3、数据通讯监听接口

/**

* Created by wangjingyun on 2017/6/7.

*

* 用于拉动后出发数据请求通信

*/

public interfacePullListener {

voidpullToRefresh(RefreshAndLoadNotify refreshAndLoad);

voidpullToLoadMore(RefreshAndLoadNotify refreshAndLoad);

}

4、使用：首先继承BaseRecyclerAdapter

其次在自己的activity里实现

private booleanrefreshing=false,loading=false;

yourAdapter.registerRefreshAndLoadMoreListener(recy_live_pub,swip_live_pub,newPullListener() {

@Override

public void pullToRefresh(RefreshAndLoadNotify refreshAndLoad) {

refreshing=true;

getLivePubList(refreshAndLoad);//异步请求数据，拿到数据后刷新页面

}

@Override

public void pullToLoadMore(RefreshAndLoadNotify refreshAndLoad) {

//TODO用法同刷新不在赘述

}

});

public void getLivePubList(RefreshAndLoadNotify refreshAndLoad){

//TODO异步请求拿数据

refreshAndLoad.refreshNotify(list);//异步请求拿到结果后在主线程执行

}