Playground App 无法将类型“LLAppDelegateProxy”的值转换为“SwiftUI.AppDelegate”

Question

我的 playground 应用程序因这个错误而崩溃。不确定发生了什么或如何解决这个

Thread 1: signal SIGABRT

@main
    struct PlaygroundApp: App {
        @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate: AppDelegate
    
        var body: some Scene {
            WindowGroup {
                ContentView()
            }
        }
    }
    
    public class AppDelegate: NSObject, UIApplicationDelegate {
        static var orientationLock: UIInterfaceOrientationMask = .all
    
        public func application(_ application: UIApplication, supportedInterfaceOrientationsFor window: UIWindow?) -> UIInterfaceOrientationMask {
            AppDelegate.orientationLock
        }
    }

Answer 1

func body

的

App

应该返回

some Scene

，而不是

some View

，例如

var body: some Scene {
    WindowGroup {
        ContentView()
    }
}

如果你尝试在 Xcode 中编译你会得到更好的错误信息：

Candidate 不能推断'Body' = 'some View' 因为'some View' 不是标称类型所以不符合'Scene'