创造iPhone等待图标

.h:

　　UIActivityIndicatorView* progressView;

.m:

　　// show the waiting symbol

 　　progressView = [[UIActivityIndicatorView alloc]

 　　initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];

　　[progressView setCenter:CGPointMake(160.0f, 240.0f)];

　　[progressView startAnimating];

　　[self.view addSubview:progressView];

　　// dismiss the waiting symbol

　　[progressView removeFromSuperview];

　　[progressView stopAnimating];

　　[progressView release];