Apple官方SwiftUI教程运行报错

1、列表和导航教程中 SceneDelegate.swift错误

解决方法:修改SceneDelegate.swift 14行,使用LandmarkList不是LandmarkDetail

window.rootViewController = UIHostingController(rootView: LandmarkList())

2、处理用户输入教程中 预览错误

解决方法:取消对LandmarkDetail初始化程序的更改,只添加environmentObject(_ :)修饰符

struct LandmarkDetail_Preview: PreviewProvider {
    static var previews: some View {
        LandmarkDetail(landmark: landmarkData[0])
            .environmentObject(UserData())
    }
}

Xcode 11 Beta 4 Release Notes

Apple官方SwiftUI教程运行报错