How to center UIActivityIndicator?

SOLVED: Check below for the solution to my problem.

Hey SO,

I'm having trouble centering the UIActivityIndicator in the center of the view. As you can see here, it's a little farther down vertically than it should be. What I have is a UIScrollView that later adds a UIImage subview. Before the UIImage loads though, I have this UIActivityIndicator to show that the image is loading.

- (void)viewDidLoad
{

    [super viewDidLoad];
    self.scrollView.backgroundColor = [UIColor blackColor];
    UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc]       initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    spinner.center = self.view.center;

    [spinner startAnimating];
    [self.view addSubview:spinner];

Any ideas on how I could get the center CGPoint and set the UIActivityIndicator there? I'm not sure why self.view.center doesn't work.

Thanks in advance.

EDIT: I had to account for the height of the navigation bar and the tab bar. The code I had to add was :

float navigationBarHeight = [[self.navigationController navigationBar] frame].size.height;
float tabBarHeight = [[[super tabBarController] tabBar] frame].size.height;
spinner.center = CGPointMake(self.view.frame.size.width / 2.0, (self.view.frame.size.height  - navigationBarHeight - tabBarHeight) / 2.0);