ios自定义hub指示器

UIView * loadingView = [[ UIView alloc ] initWithFrame : CGRectMake (( self . view . frame . size . width - 80 ) / 2.0f , ([ UIScreen mainScreen ]. bounds . size . height - 80.f )/ 2.0f , 80.0f , 80.0f )];

    [loadingView setBackgroundColor:[UIColor grayColor]];

    [loadingView.layer setCornerRadius:10.0f];

    [loadingView.layer setMasksToBounds:YES];

    UIActivityIndicatorView *loading = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];

    [loading startAnimating];

    [loading setFrame:CGRectMake(30.f, 30.0f, 20.0f, 20.0f)];

    [loadingView addSubview:loading];

    [self.view addSubview:loadingView];

    [loadingView setHidden:NO];