Control.OnHelpRequested(HelpEventArgs) Method

Definition

引发 HelpRequested 事件。Raises the HelpRequested event.

protected:
 virtual void OnHelpRequested(System::Windows::Forms::HelpEventArgs ^ hevent);
protected virtual void OnHelpRequested (System.Windows.Forms.HelpEventArgs hevent);
abstract member OnHelpRequested : System.Windows.Forms.HelpEventArgs -> unit
override this.OnHelpRequested : System.Windows.Forms.HelpEventArgs -> unit
Protected Overridable Sub OnHelpRequested (hevent As HelpEventArgs)

Parameters

hevent
HelpEventArgs

一个包含事件数据的 HelpEventArgsA HelpEventArgs that contains the event data.

Remarks

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.

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

Notes to Inheritors

在派生类中重写 OnHelpRequested(HelpEventArgs) 时,一定要调用基类的 OnHelpRequested(HelpEventArgs) 方法,以便已注册的委托对事件进行接收。When overriding OnHelpRequested(HelpEventArgs) in a derived class, be sure to call the base class's OnHelpRequested(HelpEventArgs) method so that registered delegates receive the event.

Applies to

See also