SwiftUI:如何只为 iPhone 显示一些工具栏按钮

Question

我有一组工具栏按钮，只有在设备是 iPhone(不是 iPad)时才应该显示。
以下代码失败并出现此错误:

Closure containing control flow statement cannot be used with result builder 'ToolbarContentBuilder'

我确实理解它为什么会失败，但我无法想出一个解决方案来实现我所需要的。

import SwiftUI

struct ContentView: View {
    var body: some View {
        NavigationView {
            List {
                NavigationLink(
                    destination: Hello(),
                    label: {
                        Text("Hello")
                    })
            }
        }
    }
}

struct Hello: View {
    var body: some View {
        Text("Hello World")
            .toolbar() {
                if UIDevice.current.userInterfaceIdiom == .phone {
                    ToolbarItem(placement: .navigationBarTrailing) {
                        Button(action: {
                            // do something
                        }, label: {
                            Text("Button1")
                        })
                    }
                    ToolbarItem(placement: .navigationBarTrailing) {
                        Button(action: {
                            // do something
                        }, label: {
                            Text("Button2")
                        })
                    }
                }
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button(action: {
                        // do something
                    }, label: {
                        Text("Button3")
                    })
                }
            }
    }
}

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

我很高兴创建一个单独的函数来实现它。我根本不知道该怎么做。

Answer 1

可能你想要这个

struct Hello: View {
    var body: some View {
        Text("Hello World")
            .toolbar() {
                ToolbarItemGroup(placement: .navigationBarTrailing) {
                    if UIDevice.current.userInterfaceIdiom == .phone {
                        Button(action: {
                            // do something
                        }, label: {
                            Text("Button1")
                        })
                        Button(action: {
                            // do something
                        }, label: {
                            Text("Button2")
                        })
                    }
                    Button(action: {
                        // do something
                    }, label: {
                        Text("Button3")
                    })
                }
            }
    }
}