UIStatusBarStyle doesn't change

Question

I'm working on a swift app and I wanna change the UIStatusBarStyle according to the app's theme (there are 2 options - light and dark theme). I have set View controller-based status bar appearance to NO in the info.plist and in the UIViewController I tried to set it based on the current theme like so:

override var preferredStatusBarStyle: UIStatusBarStyle {
    return Theme.current.statusBarStyle
}


protocol ThemeProtocol { 
    // Status Bar
    var statusBarStyle: UIStatusBarStyle { get } 
}

class Theme {
    static var current: ThemeProtocol = LightTheme()
}

class LightTheme: ThemeProtocol {
    // Status Bar 
    var statusBarStyle: UIStatusBarStyle = .default

}

class DarkTheme: ThemeProtocol {
    // Status Bar 
    var statusBarStyle: UIStatusBarStyle = .lightContent

}

No result really. I tried to test it by returning only: return .lightContent but that didn't change the status bar either.

What am I doing wrong?

UPDATE:

Okay, so this is what I'm trying to do and it's not working.

    fileprivate func applyTheme() {

    statusBarStyle = UserDefaults.standard.bool(forKey: SelectedThemeKey) ? .default : .lightContent
    self.setNeedsStatusBarAppearanceUpdate()

}

override var preferredStatusBarStyle: UIStatusBarStyle {
    return statusBarStyle
}

And it's not working. Despite changing the theme, the status bar always remain with the default style. applyTheme() is called in viewDidLoad() and viewWillAppear()

Answer 1

You need to call this method after any change

setNeedsStatusBarAppearanceUpdate()

//

class ViewController: UIViewController {

    var current = UIStatusBarStyle.default

    @IBAction func changeClicked(_ sender: Any) {
        current = current == .default ? .lightContent : .default
        self.setNeedsStatusBarAppearanceUpdate()
    }
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }
    override  var preferredStatusBarStyle: UIStatusBarStyle {
        return current
    }

}