UIActivityIndicatorView用法

1、基本用法：

UIActivityIndicatorView * activityIndicatorView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
activityIndicatorView.bounds = CGRectMake(0, 0, 50, 50);
activityIndicatorView.center = self.view.center;
[self.view addSubview:activityIndicatorView];
[activityIndicatorView startAnimating];

activityIndicatorView.hidesWhenStopped = YES;//动画停止的时候隐藏
// [activityIndicatorView stopAnimating];//停止动画


activityIndicatorView.activityIndicatorViewStyle = UIActivityIndicatorViewStyleGray



activityIndicatorView.activityIndicatorViewStyle = UIActivityIndicatorViewStyleWhite