SwiftUI: unwanted split view on iPad

问题

Problem: a view on Pad shows up with unwanted split view.

My current setup is: Catalina OSX beta 5 + Xcode 11 Beta 5

Here is the code I used, with a Navigation View and a Navigation Title:

import SwiftUI

struct SwiftUIView: View {
    var body: some View {
        NavigationView {
            Text("Search")
                .navigationBarTitle(Text("Search"))
        }
    }
}

#if DEBUG
struct SwiftUIView_Previews: PreviewProvider {
    static var previews: some View {
        SwiftUIView()
    }
}
#endif

When simulated on iPad (both physical device and preview) instead of a full screen view, I get this split screen view:

If I have just a view, with no NavigationView, I get a full screen view:

import SwiftUI

struct SwiftUIView: View {
    var body: some View {
        Text("Hello World!")
    }
}

#if DEBUG
struct SwiftUIView_Previews: PreviewProvider {
    static var previews: some View {
        SwiftUIView()
    }
}
#endif

How can I make a NavigationView full screen (not split screen) on iPad?

回答1:

You can apply the .navigationViewStyle(StackNavigationViewStyle()) modifier to the NavigationView!

... 
    NavigationView {
        Text("Hello world!")
    }
    .navigationViewStyle(StackNavigationViewStyle())
...

Edit: Below, I am answering Alexandre's questions from his comment:

• Why full view is not the default for iPad? That's just a choice made by Apple...

• Why this modifier goes outside of NavigationView closure, while the Navigation Title goes inside... Maybe this gives clarification: https://stackoverflow.com/a/57400873/11432719

回答2:

To use this split style for iPad but remove for iPhone:

    extension View{
    func phoneOnlyStackNavigationView() ->some View{

        if UIDevice.current.userInterfaceIdiom == .phone{
            return AnyView(self.navigationViewStyle(StackNavigationViewStyle()))
        }else{
            return AnyView(self)
        }
    }
}

来源：https://stackoverflow.com/questions/57425921/swiftui-unwanted-split-view-on-ipad