如何在 iOS 14 @main 文件中获取 UIWindow 值? [英] How to get UIWindow value in iOS 14 @main file?

问题描述

我可以通过以下实现访问 didFinishLaunchingWithOptions.但是，我需要 UIWindow 变量.我不知道如何得到它.我正在使用 Xcode 12 测试版.iOS14，SwiftUI 生命周期.

<预><代码>导入 SwiftUI@主要的struct SSOKit_DemoApp:应用{@UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegatevar主体:一些场景{窗口组{内容视图()}}}类 AppDelegate: NSObject, UIApplicationDelegate {func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) ->布尔{打印(你好世界！！！")返回真}}

解决方案

从 iOS 13 开始，可以安全地假设获取关键窗口引用的正确方法是通过 UIWindowSceneDelegate.

@main结构演示应用程序:应用程序{变量窗口:UIWindow?{守卫让场景 = UIApplication.shared.connectedScenes.first，让 windowSceneDelegate = scene.delegate 作为?UIWindowSceneDelegate，让窗口 = windowSceneDelegate.window else {返回零}返回窗口}[...]}

I can able to access didFinishLaunchingWithOptions by below implementation. But, I need UIWindow variable. I don't know how to get it. I'm using Xcode 12 beta. iOS14, SwiftUI lifecycle.

import SwiftUI

@main
struct SSOKit_DemoApp: App {
    
    @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
    
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

class AppDelegate: NSObject, UIApplicationDelegate {
    
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
        
        print("hello world!!!")
        return true
    }
}

解决方案

From iOS 13 onwards, it's safe to assume that the correct way to obtain a reference to the key window is via UIWindowSceneDelegate.

@main
struct DemoApp: App {
    
    var window: UIWindow? {
        guard let scene = UIApplication.shared.connectedScenes.first,
              let windowSceneDelegate = scene.delegate as? UIWindowSceneDelegate,
              let window = windowSceneDelegate.window else {
            return nil
        }
        return window
    }

    [...]
}

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