android使用SwipeRefreshLayout实现下拉刷

SwipeRefreshLayout可以包裹一些组件，比如recyclerview,listview,webview等，实现下拉刷新，上拉加载，实例：

• 布局文件：

<android.support.v4.widget.SwipeRefreshLayout
  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:id="@+id/swipe_refresh_widget">   <android.support.v7.widget.RecyclerView  android:id="@+id/my_recycler_view"
  android:scrollbars="vertical"
  android:layout_width="match_parent"
  android:layout_height="match_parent"/>   </android.support.v4.widget.SwipeRefreshLayout></pre>

• activity中，主要是设置刷新监听，刷新结束时，调用setRefreshing(false);隐藏刷新进度条

public class WaterfallActivity extends AppCompatActivity implements SwipeRefreshLayout.OnRefreshListener {

    private SwipeRefreshLayout mSwipeRefreshWidget; 
   @Override
  protected void onCreate(Bundle savedInstanceState)  {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);   
        ......        
        mSwipeRefreshWidget = (SwipeRefreshLayout)  findViewById(R.id.swipe_refresh_widget);    
        mSwipeRefreshWidget.setOnRefreshListener(this);    
}

    private static final int REFRESH_COMPLETE = 0X110;   private Handler mHandler = new Handler()
    {
        public void handleMessage(android.os.Message msg)
        {
            switch (msg.what)
            {
                case REFRESH_COMPLETE:
                    mSwipeRefreshWidget.setRefreshing(false);
                   break;    
}
        };
  };    
@Override
  public void onRefresh() {
        mHandler.sendEmptyMessageDelayed(REFRESH_COMPLETE, 2000);
  }

}