现在市面上新闻类的App基本上都有下拉刷新,算是一个标配吧,网上关于下拉刷新的博客也有很多,实现方式可以使用开源的PullToRefresh,自定义ListView,或者可以直接使用LineLayOut直接搞定的。不过Google在今年在support v4 19.1版本的library推出了SwipeRefreshLayout,字面上的意思就是下拉刷新,继承自ViewGroup,而如今google推出了更官方的下拉刷新组件,对于开发者而言无疑是一个好事情,比较少的代码实现需要的功能。
基本布局
先来看下简单的布局,在最外层加上SwipeRefreshLayout,但是子的View需要时可滚动的(ScrollView或ListView)
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<RelativeLayout xmlns:android= "http://schemas.android.com/apk/res/android"
xmlns:tools= "http://schemas.android.com/tools" android:layout_width= "match_parent"
android:layout_height= "match_parent"
android:paddingLeft= "@dimen/activity_horizontal_margin"
android:paddingRight= "@dimen/activity_horizontal_margin"
android:paddingTop= "@dimen/activity_vertical_margin"
android:paddingBottom= "@dimen/activity_vertical_margin" tools:context= ".MainActivity" >
<android.support.v4.widget.SwipeRefreshLayout
android:id= "@+id/swipeRefreshLayout"
android:layout_width= "wrap_content"
android:layout_height= "wrap_content"
>
<ListView
android:id= "@+id/listView"
android:layout_width= "match_parent"
android:layout_height= "wrap_content" >
</ListView>
</android.support.v4.widget.SwipeRefreshLayout>
</RelativeLayout> |
布局效果如下:
Demo实现
MainActivity中onCreate中的初始化一下SwipeLayOut,需要注意的方法是setColorScheme(), 设置进度条的颜色主题,最多能设置四种;
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myListView = (ListView) findViewById(R.id.listView); mySwipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipeRefreshLayout);
mySwipeRefreshLayout.setOnRefreshListener( this );
mySwipeRefreshLayout.setColorScheme(android.R.color.holo_blue_bright, android.R.color.holo_green_light,
android.R.color.holo_orange_light, android.R.color.holo_red_light);
listAdapter = new ArrayAdapter( this ,android.R.layout.simple_list_item_1,listIDE);
myListView.setAdapter(listAdapter);
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MainActivity中需要实现一下 SwipeRefreshLayout.OnRefreshListener
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@Override public void onRefresh() {
refreshHandler.sendEmptyMessageDelayed(REFRESH_STATUS, 1500 );
}
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最后初始化一下数据setRefreshing(boolean):,显示或隐藏刷新进度条
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private static final int REFRESH_STATUS = 0 ;
private ListView myListView;
private SwipeRefreshLayout mySwipeRefreshLayout;
private ArrayAdapter<String> listAdapter;
private List<String> listIDE = new ArrayList<String>(Arrays.asList( "Visual Studio" , "Android Studio" , "Eclipse" , "Xcode" ));
private Handler refreshHandler = new Handler()
{
public void handleMessage(android.os.Message msg)
{
switch (msg.what)
{
case REFRESH_STATUS:
listIDE.removeAll(listIDE);
listIDE.addAll(Arrays.asList( "C#" , "Java" , "C++" , "Object-C" ));
listAdapter.notifyDataSetChanged();
mySwipeRefreshLayout.setRefreshing( false );
break ;
}
};
};
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最后的效果如下:
本文转自Fly_Elephant博客园博客,原文链接:http://www.cnblogs.com/xiaofeixiang/p/4185975.html,如需转载请自行联系原作者