How to detect whether targetEnvironment is iPadOS in SwiftUI?

问题

I'd like to display different views when building for iOS and iPadOS. Currently, I know I can do

import SwiftUI

struct ContentView: View {
    #if targetEnvironment(macCatalyst)
    var body: some View {
        Text("Hello")
    }
    #else
    var body: some View {
        Text("Hello")
    }
    #endif
}

to display different views between macOS and iPadOS/iOS (introduced in Swift 4/5). But how do I differentiate between the latter? I can't seem to use targetEnvironment...

回答1:

I use this in my code:

    private var idiom : UIUserInterfaceIdiom { UIDevice.current.userInterfaceIdiom }
    private var isPortrait : Bool { UIDevice.current.orientation.isPortrait }

Then you can do this:

    var body: some View {
        NavigationView {
            masterView()

            if isPortrait {
                portraitDetailView()
            } else {
                landscapeDetailView()
            }
        }
    }

    private func portraitDetailView() -> some View {
        if idiom == .pad {
            return Text("iPadOS")
        } else {
            return Text("iOS")
        }
    }

回答2:

To return different view types you can use AnyView eraser type:

if UIDevice.current.userInterfaceIdiom == .pad {
    return AnyView(Text("Hello, World!"))
} else {
    return AnyView(Rectangle().background(Color.green))
}

来源：https://stackoverflow.com/questions/57652242/how-to-detect-whether-targetenvironment-is-ipados-in-swiftui