Question

I am trying to put a UIActivityIndicatorView on a black background, however I can’t see it spinning. Why is this? Here’s what I have:

 UIActivityIndicatorView *indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    [indicator setCenter:CGPointMake(0, 15)];
    [indicator setBackgroundColor:[UIColor blackColor]];
    [indicator startAnimating];
    [indicator hidesWhenStopped];

Answer 1

Are you actually adding your ActivityIndicator as a subview somewhere ?

If not you should add it in viewDidLoad or somewhere else appropriate using:

[self.view addSubview:indicator]

Also I’m not sure if setBackgroundColor will have the desired effect you’re looking for. I achieve this using a UIImageView and a black image with radial corners. I also like to set the Alpha value of the black image to about 75 percent. Then whenever I call startAnimating I also show the imageView, and when I call stopAnimating I hide the imageview.