PowerToys/Wox/ViewModel/BaseViewModel.cs

using System;
using System.ComponentModel;
using System.Windows.Input;

namespace Wox.ViewModel
{
    public class BaseViewModel : INotifyPropertyChanged
    {

        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }

    public class RelayCommand : ICommand
    {

        private Action<object> _action;

        public RelayCommand(Action<object> action)
        {
            _action = action;
        }

        public virtual bool CanExecute(object parameter)
        {
            return true;
        }

        public event EventHandler CanExecuteChanged;

        public virtual void Execute(object parameter)
        {
            _action?.Invoke(parameter);
        }
    }
}