SwipeRefreshLayout概述

SwipeRefrshLayout是Google官方更新的一个Widget,可以实现下拉刷新的效果。该控件集成自ViewGroup在support-v4兼容包下，不过我们需要升级supportlibrary的版本到19.1以上。

用户通过手势或者点击某个按钮实现内容视图的刷新，布局里加入SwipeRefreshLayout嵌套一个子视图如ListView、 RecyclerView等，触发刷新会通过OnRefreshListener的onRefresh方法回调，我们在这里执行页面数据的刷新，每次手势 的完成都会执行一次通知，根据滑动距离判断是否需要回调。setRefreshing（false）通过代码直接取消刷新，true则手动设置刷新调出刷 新视图。setEnabled（false）通过boolean控制是否禁用手势刷新 。

基本使用的方法如下:

1. setOnRefreshListener(OnRefreshListener):添加下拉刷新监听器
2. setRefreshing(boolean):显示或者隐藏刷新进度条
3. isRefreshing():检查是否处于刷新状态

使用非常简单，用一个简单案例来介绍SwipeRefreshLayout下拉刷新的功能。

布局文件

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"android:id="@+id/v7_refresh"android:layout_width="match_parent"android:layout_height="match_parent"android:background="@color/back"><android.support.v7.widget.RecyclerViewandroid:id="@+id/v7_recyclerView"android:layout_width="match_parent"android:layout_height="match_parent" /></android.support.v4.widget.SwipeRefreshLayout>

item.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"xmlns:app="http://schemas.android.com/apk/res-auto"android:id="@+id/cardview"app:cardCornerRadius="5dp"app:cardBackgroundColor="@android:color/white"android:layout_margin="5dp"android:layout_height="60dp"android:layout_width="match_parent"><TextViewandroid:id="@+id/menuitem_tv"android:layout_gravity="center"android:text="@string/app_name"android:layout_width="wrap_content"android:layout_height="wrap_content" /></android.support.v7.widget.CardView>

Activity

public class MainActivity extends AppCompatActivity {private SwipeRefreshLayout swipeRefreshLayout;private RecyclerView recyclerView;private List<String> list=null;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main_activity);initView();}private void initView(){swipeRefreshLayout=(SwipeRefreshLayout)findViewById(R.id.v7_refresh);recyclerView=(RecyclerView)findViewById(R.id.v7_recyclerView);//设置下拉圆圈的大小，两个值 LARGE， DEFAULTswipeRefreshLayout.setSize(SwipeRefreshLayout.LARGE);// 设定下拉圆圈的背景:默认white// swipeRefreshLayout.setProgressBackgroundColor(android.R.color.white);initData();}private void initData(){bindData();//设置刷新时动画的颜色，可以设置4个swipeRefreshLayout.setColorSchemeResources(android.R.color.holo_blue_light, android.R.color.holo_red_light, android.R.color.holo_orange_light, android.R.color.holo_green_light);swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {@Overridepublic void onRefresh() {Toast.makeText (MainActivity.this,"正在刷新",Toast.LENGTH_LONG).show();// TODO Auto-generated method stubnew Handler().postDelayed(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubToast.makeText (MainActivity.this,"刷新完成",Toast.LENGTH_LONG).show();swipeRefreshLayout.setRefreshing(false);}}, 4000);}});}private void bindData(){list=new ArrayList<>();for(int i=0;i<22;i++){list.add("Item"+(i+1));}recyclerView.setLayoutManager(new LinearLayoutManager(this));recyclerView.setHasFixedSize(true);recyclerView.setItemAnimator(new DefaultItemAnimator());MenuAdapter menuAdapter=new MenuAdapter(this,R.layout.item,list);recyclerView.setAdapter(menuAdapter);menuAdapter.setOnItemClickListener(new CommonRecyclerAdapter.OnItemClickListener() {@Overridepublic void onItemClick(RecyclerView.ViewHolder viewHolder, View view, int position) {Toast.makeText (MainActivity.this, list.get(position),Toast.LENGTH_LONG).show();}});}
}

运行效果如图：

源码点击下载