WPF Commands Return Value

using System;
using System.Windows.Input;

namespace CommandReturnValue.Commands
{
    public class CustomCommand : RoutedCommand
    {
        public delegate void ReturnValueChangedHandler(object sender, EventArgs e);
        //an event for command sources on return value change
        public event ReturnValueChangedHandler ReturnValueChanged;

        private object returnValue;

        public CustomCommand(string Name, Type OnerType): base(Name, OnerType)
        {
        }

        //the return value
        public object ReturnValue
        {
            get
            {
                return returnValue;
            }
            set
            {
                returnValue = value;
                ReturnValueChanged(this, new EventArgs());
            }
        }
    }
}