RelayCommand.cs

using System;
using System.Windows.Input;

namespace RouteEditorCS
{
    /// <summary>
    /// A Helper class to bind UI Events to simple Map methods.
    /// </summary>
    public class RelayCommand : ICommand
    {
        private readonly Action _execute;
        private readonly Func<bool> _canExecute;

        public RelayCommand (Action execute, Func<bool> canExecute = null)
        {
            _execute = execute;
            _canExecute = canExecute;
        }

        public event EventHandler CanExecuteChanged
        {
            add => CommandManager.RequerySuggested += value;
            remove => CommandManager.RequerySuggested -= value;
        }

        public bool CanExecute (object parameter) => _canExecute == null || _canExecute();

        public void Execute (object parameter) => _execute();
    }
}