Control.OnDragOver(DragEventArgs) 方法

定义

引发 DragOver 事件。Raises the DragOver event.

protected:
 virtual void OnDragOver(System::Windows::Forms::DragEventArgs ^ drgevent);
protected virtual void OnDragOver (System.Windows.Forms.DragEventArgs drgevent);
abstract member OnDragOver : System.Windows.Forms.DragEventArgs -> unit
override this.OnDragOver : System.Windows.Forms.DragEventArgs -> unit
Protected Overridable Sub OnDragOver (drgevent As DragEventArgs)

参数

drgevent
DragEventArgs

包含事件数据的 DragEventArgsA DragEventArgs that contains the event data.

实现

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.

OnDragOver 方法还允许派生类对事件进行处理而不必附加委托。The OnDragOver 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 OnDragOver(DragEventArgs) 时,一定要调用基类的 OnDragOver(DragEventArgs) 方法,以便已注册的委托对事件进行接收。When overriding OnDragOver(DragEventArgs) in a derived class, be sure to call the base class's OnDragOver(DragEventArgs) method so that registered delegates receive the event.

适用于

另请参阅