一.下拉刷新
话不多说，前段时间做项目的时候刚用到过，分享出来集思广益，欢迎指出不足。本文主要利用SwipeRefreshLayout嵌套Recycleview实现简单的下拉刷新功能。
1.XML文件：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/swiperefreshlayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:scrollbars="vertical" />
</android.support.v4.widget.SwipeRefreshLayout>
</LinearLayout>
2.代码：Activity的OnCreate方法里只要添加几行代码就可实现下拉刷新的效果
swiperefreshlayout.setOnRefreshListener(this);
swiperefreshlayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
//发送网络请求
sendRequest();
//停止刷新
swiperefreshlayout.setRefreshing(false);
//刷新RecycleView
mRecycleViewAdapter.notifyDataSetChanged();
}
});
二.上拉加载更多
看过网上很多关于上拉加载更多的文章，最后总结测试了一下，就有了适合自己的简单的上拉加载更多。主要采用Recycleview设置一个FootViewHolder，并监听Recycleview的滑动状态来实现效果。直接贴代码吧（Copy不能运行，只能自己截取有用的部分加以利用，耐着性子看完，相信会有收获哦）
1.XML文件：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/swiperefreshlayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:scrollbars="vertical" />
</android.support.v4.widget.SwipeRefreshLayout>
2.代码(主要为网络请求到的数据Copy无效，其他各位看官随意蹂躏)：
1.Activity:
public class MyActivity extends AppCompatActivity {
private NoticeAdapter adapter;
private RecyclerView noticeRecyclerview;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initData();
}
private void initData() {
//news为你第一次发送网络请求获取到的List集合,这里就不贴了
adapter = new NoticeAdapter(this,news);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
noticeRecyclerview.setLayoutManager(linearLayoutManager);
noticeRecyclerview.setAdapter(adapter);
noticeRecyclerview.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL));
noticeRecyclerview.addOnScrollListener(monScrollListener);
adapter.notifyDataSetChanged();
}
//本段可直接Copy，作用是监听Recycleview是否滑动到底部
private int mLastVisibleItemPosition;
private RecyclerView.OnScrollListener monScrollListener = new RecyclerView.OnScrollListener() {
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
if (layoutManager instanceof LinearLayoutManager) {
mLastVisibleItemPosition = ((LinearLayoutManager) layoutManager).findLastVisibleItemPosition();
}
if (adapter != null) {
if (newState == RecyclerView.SCROLL_STATE_IDLE
&& mLastVisibleItemPosition + 1 == adapter.getItemCount()) {
//发送网络请求获取更多数据
sendMoreRequest();
}
}
}
};
private void sendMoreRequest() {
//可直接查看下面onResponse方法，网络请求操作不必细看
String url = Constant.BaseUrl + "getNews";
final String s = MD5Tools.MD5(MD5Tools.MD5("NEW"));
OkHttpUtils.post().url(url)
.addParams("FKEY", s)
.build()
.execute(new StringCallback() {
@Override
public void onError(Call call, Exception e, int id) {
}
@Override
public void onResponse(String response, int id) {
NoticeBean noticeBean = new Gson().fromJson(response.toString(), NoticeBean.class);
//result == 1表示请求成功
if (noticeBean.getResult()== 1){
//判断请求的数据集合是否不为空
if (noticeBean.getNews().size()!=0){
//不为空，则添加数据
adapter.addList(noticeBean.getNews());
}else {
//为空，则调用adapter里面的方法隐藏FootView
adapter.setIsLoadMore();
}
}
}
});
}
}
2.Adapter:
public class NoticeAdapter extends RecyclerView.Adapter{
private List<NoticeBean.NewsBean> list;
private Context mContext;
//上拉加载更多布局
public static final int view_Foot = 1;
//主要布局
public static final int view_Normal = 2;
//是否隐藏
public boolean isLoadMore = false;
public NoticeAdapter(Context mContext, List<NoticeBean.NewsBean> list) {
this.list = list;
this.mContext = mContext;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType ==view_Normal ){
NoticeItemView noticeItemView = new NoticeItemView(mContext);
NoticeViewHolder viewHolder = new NoticeViewHolder(noticeItemView);
return viewHolder;
}else {
FootView view = new FootView(mContext);
FootViewHolder footViewHolder = new FootViewHolder(view);
return footViewHolder;
}
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (position == getItemCount()-1){
FootView itemView = (FootView) holder.itemView;
if (isLoadMore){
itemView.setData();
}else {
itemView.setVisibility(View.VISIBLE);
}
}else {
NoticeItemView itemView = (NoticeItemView) holder.itemView;
itemView.setData(list.get(position));
}
}
@Override
public int getItemCount() {
return list.size()+1;
}
@Override
public int getItemViewType(int position) {
if (position == getItemCount()-1){
return view_Foot;
}else {
return view_Normal;
}
}
public void addList(List<NoticeBean.NewsBean> news) {
list.addAll(news);
notifyDataSetChanged();
}
public void setIsLoadMore() {
this.isLoadMore = true;
notifyDataSetChanged();
}
static class NoticeViewHolder extends RecyclerView.ViewHolder {
public NoticeViewHolder(View itemView) {
super(itemView);
}
}
static class FootViewHolder extends RecyclerView.ViewHolder {
public FootViewHolder(View itemView) {
super(itemView);
}
}
}
3.FootView为自定义控件，NoticeItemView和FootView大同小异，就不贴代码了，FootView代码如下
public class FootView extends RelativeLayout {
@BindView(R.id.foot_view_progressbar)
ProgressBar footViewProgressbar;
public FootView(Context context) {
this(context, null);
}
public FootView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
View.inflate(getContext(), R.layout.foot_view, this);
ButterKnife.bind(this,this);
}
public void setData() {
footViewProgressbar.setVisibility(GONE);
}
}
4.FootView的XML文件：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ProgressBar
android:id="@+id/foot_view_progressbar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"/>
</LinearLayout>
四.后续会更新源码至GitHub,有兴趣的同学可关注微信公众号MiHomes。
末尾：移动互联&人力资源交流群，可加微信zy666128入群交流。
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