Dark_Mode

Dark Mode

Checking User Style

switch UIScreen.main.traitCollection.userInterfaceStyle { 
	case .light: //light mode 
	case .dark: //dark mode 
	case .unspecified: //the user interface style is not specified
}

Override the App user style

You could use User Defaults to save the in app settings for different themes.

Xcode assets

Utilize Color Set in Xcode with “Any” & “Dark” Mode. To better update the application with dynamic settings.

Dynamic colors

swiftbysundell | dynamic-colors-in-swift/

Detect UI Appearance Change

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

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

SO | iOS 13 tableview cell dark mode

SO | iOS 13 detect dark mode changes

Single View Override

First retrieve color scheme of the app.

SwiftUI

Specific single view passed with environment or

.environment(\.colorScheme, .light) // or .dark
// OR
.preferredColorScheme(.dark)

Entire App Color scheme

UIKit

Each UIView has access to the window, So you can use it to set the . overrideUserInterfaceStyle value to any scheme you need.

myView.window?.overrideUserInterfaceStyle = .dark

SwiftUI

Copied from StackOverflow post

First you need to access the window to change the app colorScheme that called UserInterfaceStyle in UIKit.

I used this in SceneDelegate:

private(set) static var shared: SceneDelegate?

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
    Self.shared = self
    ...
}

Then you need to bind an action to the toggle. So you need a model for it.

struct ToggleModel {
    var isDark: Bool = true {
        didSet { 
            SceneDelegate.shared?.window!.overrideUserInterfaceStyle = isDark ? .dark : .light 
        }
    }
}

At last, you just need to toggle the switch:

struct ContentView: View {
     @State var model = ToggleModel()

     var body: some View {
         Toggle(isOn: $model.isDark) {
             Text("is Dark")
        }
    }
}