How to change status bar text color immediately in Swift in iOS 13

Question

I'm using Swift 5.1 and Xcode 11.1 and I've currently finished implementing Dark Mode design.

Theme updates immediately after user changes theme style in settings page with this code.

guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {
   return
}
appDelegate.changeTheme(themeVal)

// App Delegate File
...
func changeTheme(themeVal: String) {
   if #available(iOS 13.0, *) {
       switch AppState.appThemeStyle {
       case "dark":
           window?.overrideUserInterfaceStyle = .dark
           break
       case "light":
           window?.overrideUserInterfaceStyle = .light
           break
       default:
           window?.overrideUserInterfaceStyle = .unspecified
       }
   }
}

But the problem is that I can't see status bar text because status bar text color and view color is same.

Could anyone please suggest me good solution? Thanks.

Mojtaba Hosseini · Accepted Answer · 2019-10-28T11:41:23.077

9

Status bar color is not global (by default) and if you set that to not ViewControllerBased, you can't change it anymore. So you need to change set it inside any view you need like this:

var statusBarStyle = UIStatusBarStyle.default { didSet { setNeedsStatusBarAppearanceUpdate() } }
override var preferredStatusBarStyle: UIStatusBarStyle { statusBarStyle }

these two variables help you to change the status bar. Note that you can call setNeedsStatusBarAppearanceUpdate inside an animation block to make it animatable.

to detect when UserInterfaceStyle change (and update statusBar color accordingly), all views and viewControllers have delegate function for that. So knowing that:

override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
    super.traitCollectionDidChange(previousTraitCollection)

    if traitCollection.hasDifferentColorAppearance(comparedTo: previousTraitCollection) {
        updateStatusBarColor()
    }
}

And this is the function:

func updateStatusBarColor() {
    switch traitCollection.userInterfaceStyle {
    case .unspecified: statusBarStyle = .default
    case .light: statusBarStyle = .darkContent
    case .dark: statusBarStyle = .lightContent
    }
}

Note that:

the ParentViewController defines the statusBarColor. So if you are using general navigationController or tabBarController, A custom class for them with these codes should be enough.

edited Oct 28 '19 at 11:41

answered Oct 28 '19 at 10:57

Mojtaba Hosseini

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Can you please re-review my question? do we need traitCollectionDidChange function? I think we can do it in changeTheme() func I made? and what contents will be in myFunctionThatUpdatesStatusBar? – Ioan Moldovan Oct 28 '19 at 11:01
I have added the *function* and the answer is **yes**. Because you want it to be synced with `UserInterfaceStyle` changes. Didn't you? – Mojtaba Hosseini Oct 28 '19 at 11:05
I tried with you solution , sorry but it doesn't work. – Ioan Moldovan Oct 28 '19 at 11:08
How come status bar style value can be returned to setNeedsStatusBarAppearnace ? – Ioan Moldovan Oct 28 '19 at 11:09
That is not **return**. That is **didSet** property observer. – Mojtaba Hosseini Oct 28 '19 at 11:10
This code is instant and tested! I think you use this code in a wrong way. Can you tell me your view hierarchy and where did you put this code ? – Mojtaba Hosseini Oct 28 '19 at 11:11
And view hierarchy? Isn't `BaseViewController` inside a `NavigationController` or `TabBarController`? – Mojtaba Hosseini Oct 28 '19 at 11:12
It's inside NavigationController – Ioan Moldovan Oct 28 '19 at 11:13
So follow the very last line of the answer and put this inside `BaseNavigationController` ;) – Mojtaba Hosseini Oct 28 '19 at 11:14
UpdateStatusBarColor got called but statusbar color doesn't change – Ioan Moldovan Oct 28 '19 at 11:23
I asked for view hierarchy! maybe the navigation controller is inside another controller or something. – Mojtaba Hosseini Oct 28 '19 at 11:25
2

It didn't work because I set UIViewControllerBasedStatusBarAppearance to false in Info.plist. Sorry my mistake. – Ioan Moldovan Oct 28 '19 at 11:59
No problem. But I have mentioned that in the first line. – Mojtaba Hosseini Oct 28 '19 at 12:01
I forgot to check, my bad :( – Ioan Moldovan Oct 28 '19 at 12:02

How to change status bar text color immediately in Swift in iOS 13

1 Answers1

Note that:

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