[IOS] iphone 弹出加载中对话框 UIAlertView

//显示加载中对话框   
- (void)dialogShow {       
    baseAlert = [[UIAlertView alloc] initWithTitle:@"Loading" message:nil delegate:self cancelButtonTitle:nil otherButtonTitles: nil];   
    [baseAlert show];   
       
    //Create and add the activity indicator   
    UIActivityIndicatorView *aiv = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];   
    aiv.center = CGPointMake(baseAlert.bounds.origin.x + baseAlert.bounds.size.width/2, baseAlert.bounds.origin.y +baseAlert.bounds.size.height/2);   
    [aiv startAnimating];   
    [baseAlert addSubview:aiv];     
       
    //Auto dismiss after 3 seconds   
    //[self performSelector:@selector(dialogDismiss) withObject:nil afterDelay:3.0f];   
}   
//取消对话框显示   
- (void) dialogDismiss {   
    [baseAlert dismissWithClickedButtonIndex:0 animated:NO];   
}