ToolStripDropDownItem.OnDropDownOpened(EventArgs) ToolStripDropDownItem.OnDropDownOpened(EventArgs) ToolStripDropDownItem.OnDropDownOpened(EventArgs) ToolStripDropDownItem.OnDropDownOpened(EventArgs) Method

定义

引发 DropDownOpened 事件。Raises the DropDownOpened event.

protected public:
 virtual void OnDropDownOpened(EventArgs ^ e);
protected internal virtual void OnDropDownOpened (EventArgs e);
abstract member OnDropDownOpened : EventArgs -> unit
override this.OnDropDownOpened : EventArgs -> unit
Protected Friend Overridable Sub OnDropDownOpened (e As EventArgs)

参数

e
EventArgs EventArgs EventArgs EventArgs

包含事件数据的 EventArgsAn EventArgs that contains the event data.

注解

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.

OnDropDownOpened 方法还允许派生类对事件进行处理而不必附加委托。The OnDropDownOpened 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

当在OnDropDownOpened(EventArgs)派生类中重写时, 请确保调用基类的OnDropDownOpened(EventArgs)方法, 以便注册的委托接收事件。When overriding OnDropDownOpened(EventArgs) in a derived class, be sure to call the base class' OnDropDownOpened(EventArgs) method so that registered delegates receive the event.

适用于