SwiftUI NavigationView displaying incorrectly

Question

I'm learning SwiftUI and following through with Apple's 'Landmark' tutorial and then taking the examples and trying to make my own using that knowledge.

However, I'm really missing some understanding because I can't see why I'm getting non-standard behaviour.

Apples code:

struct CategoryHome: View
{
    var body: some View
    {
        NavigationView
        {
            Text("Landmarks Content")
                .navigationBarTitle(Text("Featured"))
        }
    }
}

And it produces this:

My code:

struct ContentView: View
{
    @State private var selection: String? = nil
    
    var body: some View
    {
        NavigationView
        {
            NavigationLink(destination: Text("Second View"), tag: "Second", selection: $selection) { EmptyView() }
            NavigationLink(destination: Text("Third View"),  tag: "Third",  selection: $selection) { EmptyView() }
            NavigationLink(destination: Text("Forth View"),  tag: "Forth",  selection: $selection) { EmptyView() }
        
            VStack
            {
                Text("Content View")
                Spacer()
                Button("Press to goto 2nd view", action: { self.selection = "Second" })
                Button("Press to goto 3rd view", action: { self.selection = "Third" })
                Button("Press to goto 4th view", action: { self.selection = "Forth" })
                Spacer()
            }
        }
        .navigationBarTitle("Home")
    }
}

And it produces this:

This is on the iPhone 11 simulator.

Can someone please explain, simply, why these are so different and why I'm not getting the results I want (which is a home 'screen' with a title, 3 buttons, when in portrait on an iPhone.

Answer 1

NavigationView expects inside one view (not a bulk of views), so below is possible solution (tested with Xcode 12 / iOS 14):

struct ContentView: View
{
    @State private var selection: String? = nil
    
    var body: some View
    {
        NavigationView
        {
            VStack
            {
                Text("Content View")
                Spacer()
                Button("Press to goto 2nd view", action: { self.selection = "Second" })
                Button("Press to goto 3rd view", action: { self.selection = "Third" })
                Button("Press to goto 4th view", action: { self.selection = "Forth" })
                Spacer()
            }
            .background(Group {
                    NavigationLink(destination: Text("Second View"), tag: "Second", selection: $selection) { EmptyView() }
                    NavigationLink(destination: Text("Third View"),  tag: "Third",  selection: $selection) { EmptyView() }
                    NavigationLink(destination: Text("Forth View"),  tag: "Forth",  selection: $selection) { EmptyView() }
            })
                .navigationBarTitle("Home")
        }
    }
}