How to remove the default Navigation Bar space in SwiftUI NavigiationView

Question

I am new to SwiftUI (like most people) and trying to figure out how to remove some whitespace above a List that I embedded in a NavigationView

In this image, you can

Answer 1

I have had a similar problem when working on an app where a TabView should be displayed once the user is logged in.

As @graycampbell suggested in his comment, a TabView should not be embedded in a NavigationView, or else the "blank space" will appear, even when using .navigationBarHidden(true)

I used a ZStack to hide the NavigationView. Note that for this simple example, I use @State and @Binding to manage the UI visibility, but you may want to use something more complex such as an environment object.

struct ContentView: View {

    @State var isHidden = false

    var body: some View {
        
        ZStack {
            if isHidden {
                DetailView(isHidden: self.$isHidden)
            } else {
                NavigationView {
                    Button("Log in"){
                        self.isHidden.toggle()
                    }
                    .navigationBarTitle("Login Page")
                }
            }
        }
    }
}

When we press the Log In button, the initial page disappears, and the DetailView is loaded. The Login Page reappears when we toggle the Log Out button

struct DetailView: View {
    
    @Binding var isHidden: Bool
    
    var body: some View {
        TabView{
            NavigationView {
                Button("Log out"){
                    self.isHidden.toggle()
                }
                .navigationBarTitle("Home")
            }
            .tabItem {
                Image(systemName: "star")
                Text("One")
            }
        }
    }
}