UIWebView *_webView;
//活动指示器
activityV=[[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];//风格
activityV.frame=CGRectMake(100, 100, 100, 100);
activityV.backgroundColor=[UIColor blueColor];
activityV.hidden=YES;
[_webView addSubview: activityV];
//开始转动，停止转动
[activityV startAnimating];
[activityV stopAnimating];
活动指示器
原文：http://www.cnblogs.com/liuyingjie/p/5006815.html
