UIStatusBarStyle doesn't change

问题

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()

回答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
    }

}

回答2:

First of all, your code makes no sense. You say

I have set View controller-based status bar appearance to NO in the info.plist and in the UIViewController I tried to set it

So on the one hand you tell the runtime, do not listen to my view controller. Then you complain when the runtime doesn't listen to your view controller!

Second, keep in mind that your view controller gets no say in the status bar appearance unless it is the top-level view controller (or the top-level view controller deliberately defers to it). If your view controller is inside a navigation controller, for example, its statusBarStyle is completely irrelevant.

回答3:

First

if you are trying to change StatusBarStyle with UIApplication.shared.statusBarStyle = .default, then you should set View controller-based status bar appearance to be NO.

in this way, you need to control UIApplication.shared.statusBarStyle by yourself in everywhere; e.g viewWillAppear / viewWillDisappear.

but this method is deprecated after iOS 9.

Now I suggest you learn the new way:

please set View controller-based status bar appearance to be YES, and

override UIViewController's preferredStatusBarStyle to handle it.

override var preferredStatusBarStyle: UIStatusBarStyle {
    return .default
}

but it still not working, why?

in your case, I guess that UIViewController is one of viewControllers of UINavigationController.

if you used UINavigationController, you should override preferredStatusBarStyle in UINavigationController.

maybe you will say that I need to set different status bar style with difference view controllers, it is okay.

Just override childForStatusBarStyle in UINavigationController like this

override var childForStatusBarStyle: UIViewController? {
    return topViewController
}

then override preferredStatusBarStyle in UIViewController you want to change.

you can also make it by extension like this

extension UINavigationController {
    override open var childForStatusBarStyle: UIViewController? {
        return topViewController
    }
}

来源：https://stackoverflow.com/questions/51799469/uistatusbarstyle-doesnt-change

标签

swift

uistatusbar