How to add check mark to menu item and changes action based on selection in SwiftUI?

Question

I have a ToolbarItem that when tapped, brings a menu of either Fahrenheit or Celsius. Right now I have that if the user taps on "Celsius" the temperatures will change to celsius unit and vice versa. However, I would like to add a check mark when the user selects Fahrenheit or Celsius and have it change when they select it. Here is my code. I've tried utilizing Picker but not sure how to add the action or a button within it.

 .toolbar {
                ToolbarItem(placement: .navigationBarTrailing) {
                    Menu {
                        Button {
                            isCelsius = false
                        } label: {
                            Text("Fahrenheit °F")
                        }
                        Button {
                            isCelsius = true
                        } label: {
                            Text("Celsius °C")
                        }

                    } label: {
                        Image(systemName: "list.dash")
                    }
                    

                    
                }//toolbar item
            }//toolbar

Answer 1

You can put a Picker inside the Menu:
The .tag()s connect the selection to the state var.

            .toolbar {
                ToolbarItem(placement: .navigationBarTrailing) {
                    Menu {
                        Picker("", selection: $isCelsius) {
                            Text("Fahrenheit °F").tag(false)
                            Text("Celsius °C").tag(true)
                        }
                    } label: {
                        Image(systemName: "list.dash")
                    }
                }
            }