Menu.OnPreRender(EventArgs) 方法
定义
protected public:
override void OnPreRender(EventArgs ^ e);
protected internal override void OnPreRender (EventArgs e);
override this.OnPreRender : EventArgs -> unit
Protected Friend Overrides Sub OnPreRender (e As EventArgs)
参数
注解
此 OnPreRender 方法由 Menu 控件调用以引发 PreRender 事件。The OnPreRender method is called by the Menu control to raise the PreRender event. 在扩展类时,控件开发人员通常会使用此方法 Menu 。It is generally used by control developers when extending the Menu class.
引发事件时,将通过委托调用事件处理程序。Raising an event invokes the event handler through a delegate. 有关详细信息,请参阅处理和引发事件。For more information, see Handling and Raising Events.
OnPreRender 方法还允许派生类对事件进行处理而不必附加委托。The OnPreRender method also allows derived classes to handle the event without attaching a delegate. 这是在派生类中处理事件的首选技术。This is the preferred technique for handling the event in a derived class.
继承者说明
在派生类中重写 OnPreRender(EventArgs) 时,一定要调用基类的 OnPreRender(EventArgs) 方法,以便已注册的委托对事件进行接收。When overriding OnPreRender(EventArgs) in a derived class, be sure to call the base class's OnPreRender(EventArgs) method so that registered delegates receive the event.