Implementing ICommand?

[ktraunmueller]

I would like to assign a command to a MenuFlyoutItem to enable or disable it at runtime (i.e., when the owning MenuBarItem is about to open):

let formatBoldItem = MenuFlyoutItem()
formatBoldItem.command = FormatBoldCommand()

where FormatBoldCommand would be something like

import WinUI
import WindowsFoundation

final class FormatBoldCommand: ICommand {

    func canExecute(_ parameter: Any!) throws -> Bool {
        return ...
    }

    func execute(_ parameter: Any!) throws {
        
    }

    lazy var canExecuteChanged: Event<EventHandler<Any?>> = ...
}

I see ICommand is implemented for example in

public enum __IMPL_Microsoft_UI_Xaml_Input {
   ...

    fileprivate class ICommandImpl: ICommand, WinRTAbiImpl {

and was wondering if that's something that's also possible in user code?

[stevenbrix]

What's your issue? If it's implementing events in swift, you want to use the '@EventSource'. See the last line of WinRTInterfaceImplementations.swift in the test app