当在UIActivityViewController上单击“取消”按钮时，如何更改NavigationController的文本颜色？

Question

The color text is white for NavigationController text but changing it to white when a user presses the share button (to show cancel button). But when user press cancel button and returns from text composing then the color remains same and not change back to white.

The completion handler is detected as I see the print in the log but it doesn't change the color.

func completionHandler(activityType: UIActivityType?, shared: Bool, items: [Any]?, error: Error?) {
    if (shared) {
        print("Cool user shared some stuff")
    }
    else {
        print("Bad user canceled sharing :(")
        UIButton.appearance(whenContainedInInstancesOf: [UINavigationBar.self]).tintColor = .white
        navigationController?.navigationBar.largeTitleTextAttributes = [
            NSAttributedStringKey.foregroundColor : UIColor.white
        ]
        navigationController?.navigationBar.titleTextAttributes = [
            NSAttributedStringKey.foregroundColor : UIColor.white
        ]

    }

}

Answer 1

Removed completion handler and all the code related to changing color for tint color and only added the following to search bar.

UIBarButtonItem.appearance(whenContainedInInstancesOf: [UISearchBar.self]).tintColor = .white

If I click on Search Bar now the cancel button color is white and when I share content through Message the composing text "cancel" button color is the default (blue).