How to set an activity indicator on Custom button

问题:

I am new to iPhone development. I want to set an activity indicator which is loaded on my custom button. Please guide me. (Example: App store --> Search --> Show 25 more (on click)).

回答1:

Add the UIActivityIndicatorView as a subview of the button:

// Create spinner
UIActivityIndicatorView *myIndicator = [[UIActivityIndicatorView alloc] 
  initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];

// Position the spinner
[myIndicator setCenter:CGPointMake(myButton.frame.size.width / 2, myButton.frame.size.height / 2)];

// Add to button
[myButton addSubview:myIndicator];

// Start the animation
[myIndicator startAnimating];