您無需再次聲明該事件。如果它是公共的并且在需要時已經(jīng)被拋出，您可以根據(jù)需要通過訂閱基類事件來處理更改。我的意思是，您可以執(zhí)行以下操作：using System;using System.Windows.Forms;namespace DRT{    internal abstract partial class DRT_ComboBox_Abstract : ComboBox    {        public DRT_ComboBox_Abstract()        {            InitializeComponent();            SelectedValueChanged += MyOwnHandler        }        protected virtual void MyOwnHandler(object sender, EventArgs args)        {            // Hmn.. now I know that the selection has changed and can so somethig from here            // This method is acting like a simple client        }    }}在S O LID類上（我相信 是這種情況ComboBox），通常有效調(diào)用訂閱者來處理某些事件的方法通常是虛擬的，一旦您從此類繼承，就允許您攔截事件處理程序調(diào)用，如果這是你想要的。這是：using System;using System.Windows.Forms;namespace DRT{    internal abstract partial class DRT_ComboBox_Abstract : ComboBox    {        public DRT_ComboBox_Abstract()        {            InitializeComponent();        }        protected override void OnSelectedValueChanged(object sender, EventArgs args)        {            // Wait, the base class is attempting to notify the subscribers that Selected Value has Changed! Let me do something before that            // This method is intercepting the event notification            // Do stuff            // Continue throwing the notification            base.OnSelectedValueChanged(sender, args);        }    }}