如何更改 SwiftUI 应用程序生命周期中的 StatusBarStyle？

How to change StatusBarStyle on SwiftUI App Lifecycle?

我已经花了很多时间试图找到一种使用新生命周期 SwiftUI App[= 将 statusBarStyle 更改为 light/dark 的方法44=].

最新帖子教状态栏怎么隐藏，我不想做，改成深色或浅色就可以了

要改颜色，我最近找到的方法是打开SceneDelegate.swift然后改window.rootViewController使用我自己的 HostingController，但它只适用于使用 UIKit App Delegate Lifecycle 的项目。使用SwiftUI App Lifecycle，不会生成SceneDelegate.swift，请问哪里可以生成？

我可以通过Xcode界面的通用设置来完成。我的问题是关于如何通过代码动态地做到这一点。

  • 目标：iOS14
  • IDE: Xcode 12 测试版 3
  • OS：MacOS 11 大苏尔

以下是我目前得到的。

Everything.swift

import Foundation
import SwiftUI

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) }
    }
}

struct LocalStatusBarStyleKey: EnvironmentKey {
    static let defaultValue: LocalStatusBarStyle = LocalStatusBarStyle()
}

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

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 = [=10=] }
    }

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

struct TitlePage: View {
    @Environment(\.localStatusBarStyle) var statusBarStyle
    @State var title: String

    var body: some View {
        Text(title).onTapGesture {
            if self.statusBarStyle.currentStyle == .darkContent {
                self.statusBarStyle.currentStyle = .default
                self.title = "isDefault"
            } else {
                self.statusBarStyle.currentStyle = .darkContent
                self.title = "isDark"
            }
        }
    }
}

struct ContainerView: View {
    var controllers: [MyHostingController<TitlePage>]
    
    init(_ titles: [String]) {
        self.controllers = titles.map { MyHostingController(rootView: TitlePage(title: [=10=])) }
    }
    
    var body: some View {
        PageViewController(controllers: self.controllers)
    }
}

struct PageViewController: UIViewControllerRepresentable {
    var controllers: [UIViewController]
    
    func makeUIViewController(context: Context) -> UIPageViewController {
        let pageViewController = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal)
        return pageViewController
    }
    
    func updateUIViewController(_ uiViewController: UIPageViewController, context: Context) {
        uiViewController.setViewControllers([controllers[0]], direction: .forward, animated: true)
    }
    
    typealias UIViewControllerType = UIPageViewController
}

MyApp.swift

import SwiftUI

@main
struct TestAppApp: App {
    var body: some Scene {
        WindowGroup {
            ContainerView(["Subscribe", "Comment"])
        }
    }
}

struct TestAppApp_Previews: PreviewProvider {
    static var previews: some View {
        Text("Hello, World!")
    }
}

以前，SceneDelegate

（代码取自 ）

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

之后，没有SceneDelegate

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            MyHostingController(rootView: ContentView())
        }
    }
}

如果您遵循上面 link 的答案并在此处应用 @main，您应该能够实现您的更改。

我的建议是您只需创建一个 AppDelegate 适配器并从那里进行您需要的任何自定义。 SwiftUI 将处理 AppDelegate 的创建并管理其生命周期。

创建 AppDelegate class:

class AppDelegate: NSObject, UIApplicationDelegate {
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
        UIApplication.shared.statusBarStyle = .darkContent
        return true
    }
}

现在在您的应用程序中：

@main
struct myNewApp: App {
    @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
    
    var body: some Scene {
        WindowGroup {
            Text("I am a New View")
        }
    }
}

这并不是一个真正的解决方案，但我能想到（并最终做到）的最好办法是强制应用程序进入暗模式。在 Info.plist 或 NavigationView { ... }.preferredColorScheme(.dark)

这也会更改状态栏。不过，您将无法更改每个视图的状态栏样式。

向 Info.plist 添加两个值：

<key>UIViewControllerBasedStatusBarAppearance</key>
<false/>
<key>UIStatusBarStyle</key>
<string>UIStatusBarStyleLightContent</string>

这适用于新的 SwiftUI 应用程序生命周期 (@main)。在 iOS14.4.

上验证