iOS の Light/Dark mode 選択の設定みたいな Picker

ContentView.swift

import PlaygroundSupport
import SwiftUI

struct ContentView: View {
    @State var selection = 0
    
    var body: some View {
        HStack {
            Button {
                self.selection = 0
            } label: {
                VStack(spacing: 10) {
                    Color.white
                        .frame(maxWidth: .infinity, maxHeight: .infinity)
                    Text("hoge")
                    if self.selection == 0 {
                        Image(systemName: "checkmark.circle.fill")
                            .imageScale(.large)
                            .foregroundColor(.blue)
                    } else {
                        Image(systemName: "circle")
                            .imageScale(.large)
                            .foregroundColor(.secondary)
                    }
                }
                .foregroundColor(.primary)
            }
            Button {
                self.selection = 1
            } label: {
                VStack(spacing: 10) {
                    Color.white
                        .frame(maxWidth: .infinity, maxHeight: .infinity)
                    Text("fuga")
                    if self.selection == 1 {
                        Image(systemName: "checkmark.circle.fill")
                            .imageScale(.large)
                            .foregroundColor(.blue)
                    } else {
                        Image(systemName: "circle")
                            .imageScale(.large)
                            .foregroundColor(.secondary)
                    }
                }
                .foregroundColor(.primary)
            }
        }
    }
}

PlaygroundPage.current.setLiveView(ContentView())