navigationBarTitle 适用于 iOS，不适用于 MacOS 应用程序

Question

以下代码在 iOS 和 Catalyst 上编译并运行得很好。但当我在 macOS 应用程序中运行它时，出现错误。这是一个已知的错误还是我做错了什么。macOS Catalina 版本 10.15.3，Xcode 版本 11.3.1。

import SwiftUI

struct ContentView: View {
    var body: some View {

        NavigationView {
            List {
                Text("Item #1")
                Text("Item #2")
            }
            .navigationBarTitle("Title", displayMode: .inline)
            .navigationBarItems(leading: Text("Add"))
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

这是我得到的错误，

Value of type 'List<Never, TupleView<(Text, Text)>>' has no member 'navigationBarTitle'

Answer 1

切换到.navigationTitle("Title")，您会发现它现在可以在 macOS、Big Sur 及更高版本上运行。

Answer 2

标题栏在 macOS 上不可用。这是接口声明：

@available(iOS 13.0, tvOS 13.0, watchOS 6.0, *)
@available(OSX, unavailable)
extension View {

    /// Hides the navigation bar for this view.
    ///
    /// This modifier only takes effect when this view is inside of and visible
    /// within a `NavigationView`.
    ///
    /// - Parameters:
    ///     - hidden: A Boolean value that indicates whether to hide the
    ///       navigation bar.
    @available(OSX, unavailable)
    public func navigationBarHidden(_ hidden: Bool) -> some View


    /// Configures the title in the navigation bar for this view.
    ///
    /// This modifier only takes effect when this view is inside of and visible
    /// within a `NavigationView`.
    ///
    /// - Parameters:
    ///     - title: A description of this view to display in the navigation
    ///       bar.
    @available(OSX, unavailable)
    public func navigationBarTitle(_ title: Text) -> some View


    /// Configures the title in the navigation bar for this view.
    ///
    /// This modifier only takes effect when this view is inside of and visible
    /// within a `NavigationView`.
    ///
    /// - Parameters:
    ///     - titleKey: A key to a localized description of this view to display
    ///       in the navigation bar.
    @available(OSX, unavailable)
    public func navigationBarTitle(_ titleKey: LocalizedStringKey) -> some View