public void setRefreshing(boolean refreshing) {
   if (mSwipeRefreshLayout == null) {
     return;
   }
   if (!refreshing) {
     // 防止刷新消失太快,让子弹飞一会儿.
     mSwipeRefreshLayout.postDelayed(
         new Runnable() {
           @Override
           public void run() {
             if (mSwipeRefreshLayout != null) {
               mSwipeRefreshLayout.setRefreshing(false);
             }
           }
         },
         1000);
   } else {
     mSwipeRefreshLayout.setRefreshing(true);
   }
 }