刚切换就让PullToRefreshListView呈现下拉状态刷新

if (HttpTool.isNetworkConnected(this)) {            // 开始就呈现下拉状态            new Handler().postDelayed(new Runnable() {                @Override                public void run() {                    pullToRefreshListView.setRefreshing(true);                }            }, 500);            //getVideoUrls();        } else {            Toast.makeText(this, "请检查网络", Toast.LENGTH_SHORT).show();        }