ios - SwiftUI:为特定 View 设置状态栏颜色

Question

我一直在尝试为我的应用程序的状态栏颜色设置一个 View 。

我已经尝试过这里列出的解决方案..' How to change Status Bar text color in iOS ' 但这为整个应用程序设置了它。

我想要的是状态栏颜色为在 SceneDelegate.swift 中设置的 rootViewController 设置白色文本，然后为所有其他 View 默认设置(根据暗模式从白色更改为黑色)。

有任何想法吗？

Answer 1

状态栏内容颜色可以根据每个 View Controller 进行修改，但 SwiftUI 最常见的情况是只使用一个 View Controller ，即根托管 View Controller 。所以它需要插入那个根 Controller 改变preferredStatusBarStyle属性，在基类中是只读的。
所以想法是覆盖默认 UIHostingController有可能改变 preferredStatusBarStyle重视和使用自定义Environment值，因此任何内部 SwiftUI subview 都可以修改该首选内容样式。
这是方法，scratch，(假设目标 Info.plist 配置正确)

class LocalStatusBarStyle { // style proxy to be stored in Environment
    fileprivate var getter: () -> UIStatusBarStyle = { .default }
    fileprivate var setter: (UIStatusBarStyle) -> Void = {_ in}

    var currentStyle: UIStatusBarStyle {
        get { self.getter() }
        set { self.setter(newValue) }
    }
}

// Custom Environment key, as it is set once, it can be accessed from anywhere
// of SwiftUI view hierarchy
struct LocalStatusBarStyleKey: EnvironmentKey { 
    static let defaultValue: LocalStatusBarStyle = LocalStatusBarStyle()
}

extension EnvironmentValues { // Environment key path variable
    var localStatusBarStyle: LocalStatusBarStyle {
        get {
            return self[LocalStatusBarStyleKey.self]
        }
    }
}

// Custom hosting controller that update status bar style
class MyHostingController<Content>: UIHostingController<Content> where Content: View {
    private var internalStyle = UIStatusBarStyle.default

    @objc override dynamic open var preferredStatusBarStyle: UIStatusBarStyle {
        get {
            internalStyle
        }
        set {
            internalStyle = newValue
            self.setNeedsStatusBarAppearanceUpdate()
        }
    }

    override init(rootView: Content) {
        super.init(rootView:rootView)

        LocalStatusBarStyleKey.defaultValue.getter = { self.preferredStatusBarStyle }
        LocalStatusBarStyleKey.defaultValue.setter = { self.preferredStatusBarStyle = $0 }
    }

    @objc required dynamic init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
}

用法..

场景委托(delegate)中的某处

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
//  ...
  window.rootViewController = MyHostingController(rootView: contentView)

内容 View 中的某处

   struct ContentView: View {
        @Environment(\.localStatusBarStyle) var statusBarStyle
    
        ...
        var body: some View {
            ZStack {
               ....
                NavigationView {
                    NavigationLink(destination:  ...) {
                        ...
                    }
                    .onAppear {
                        self.statusBarStyle.currentStyle = .lightContent
                    }
                    .onDisappear {
                         self.statusBarStyle.currentStyle = .default
                     }
                }
            }
        }
    }

backup