Styling the cancel button in a UISearchBar

You can use UIAppearance to style the cancel button without iterating subviews of the UISearchBar, but the UIButton header does not currently have any methods annotated with UI_APPEARANCE_SELECTOR.

EDIT: Drill down the subviews till you get that cancel button

But this usually returns nil until searchBar.setShowsCancelButton(true, animated: true) is called.

extension UISearchBar {

var cancelButton : UIButton? {
    if let view = self.subviews.first {
        for subView in view.subviews {
            if let cancelButton = subView as? UIButton {
                return cancelButton
            }
        }
    }
    return nil
}
}

In iOS 5.0+, you can use the appearnce proxy.

Before the search bar is showed.:

UIBarButtonItem *searchBarButton = [UIBarButtonItem appearanceWhenContainedIn:[UISearchBar class], nil];
[searchBarButton setBackgroundImage:myCancelButtonImageNormal forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
[searchBarButton setBackgroundImage:myCancelButtonImageHighlighted forState:UIControlStateHighlighted barMetrics:UIBarMetricsDefault];
[searchBarButton setTitleTextAttributes:barButtonTitleTextAttributesNormal forState:UIControlStateNormal];
[searchBarButton setTitleTextAttributes:barButtonTitleTextAttributesHighlighted forState:UIControlStateHighlighted];

If you use [UIButton appearanceWhenContainedIn:[UISearchBar class], nil], it will affect other buttons (e.g. clear button). So, you'd better not use UIButton's appearnce. Try UIBarButtonItem.