ContentElement.PreviewDragEnter 事件
定义
在输入系统报告出现以此元素为拖动目标的基础拖动事件时发生。Occurs when the input system reports an underlying drag event with this element as the drag target.
public:
event System::Windows::DragEventHandler ^ PreviewDragEnter;public event System.Windows.DragEventHandler PreviewDragEnter;member this.PreviewDragEnter : System.Windows.DragEventHandler Public Custom Event PreviewDragEnter As DragEventHandler 事件类型
注解
此事件将为 DragDrop.PreviewDragEnter 此类创建附加事件的别名，因此 PreviewDragEnter 当 ContentElement 继承为基元素时，它是类成员列表的一部分。This event creates an alias for the DragDrop.PreviewDragEnter attached event for this class, so that PreviewDragEnter is part of the class members list when ContentElement is inherited as a base element. 附加到事件的事件处理程序 PreviewDragEnter 附加到基础 DragDrop.PreviewDragEnter 附加事件，并接收相同的事件数据实例。Event handlers that are attached to the PreviewDragEnter event are attached to the underlying DragDrop.PreviewDragEnter attached event and receive the same event data instance.
路由事件信息Routed Event Information
| 标识符字段Identifier field | PreviewDragEnterEvent |
| 路由策略Routing strategy | 隧道Tunneling |
| 委托Delegate | DragEventHandler |
对应的冒泡事件为 DragEnter 。The corresponding bubbling event is DragEnter.
重写 OnPreviewDragEnter 以在派生类中实现此事件的类处理。Override OnPreviewDragEnter to implement class handling for this event in derived classes.