如何设置事件回调

Question

目前 OnNotification 从 TestInvoker 获取事件，但当从 TestInvoker 发送事件时，我也想从 HelpTextManager 获取正确的值。

这是我的代码：

public interface IHelpEventListener
{
    void OnNotification(object sender, HelpTextEventArgs args);
}

public abstract class HelpTextEventHandler
    {
        public event EventHandler<HelpTextEventArgs> Event;
        public void NotifyHelpTextManager(object sender, HelpTextEventArgs args)
        {
            Event?.Invoke(sender, args);
        }

        public void RegisterHelpTextListener(IHelpEventListener listener) => Event += listener.OnNotification;
        public void UnRegisterHelpTextListener(IHelpEventListener listener) => Event -= listener.OnNotification;
    }

class TestInvoker : HelpTextEventHandler
    {
        public bool IsHelpOnScreen()
        {
            NotifyHelpTextManager(this, new HelpTextEventArgs() { TextEventName = HelpTextEventEnum.welcome });
            return true;
        }
    }

class HelpTextManager : IHelpEventListener
    {
        public void OnNotification(object sender, HelpTextEventArgs args)
        {
            Console.WriteLine(string.Format(
                "{0} fired an event",
                sender.GetType().ToString()));

            Console.WriteLine($"name: { args.TextEventName.ToString() } DisplayOnce: { args.DisplayOnce.ToString()} ");
        }
    }