UIElement.PreviewQueryContinueDrag Event


在拖放操作期间键盘或鼠标按钮的状态改变时发生。Occurs when there is a change in the keyboard or mouse button state during a drag-and-drop operation.

 event System::Windows::QueryContinueDragEventHandler ^ PreviewQueryContinueDrag;
public event System.Windows.QueryContinueDragEventHandler PreviewQueryContinueDrag;
member this.PreviewQueryContinueDrag : System.Windows.QueryContinueDragEventHandler 
Public Custom Event PreviewQueryContinueDrag As QueryContinueDragEventHandler 


PreviewQueryContinueDrag 事件允许拖动源声明是否应取消拖放操作。The PreviewQueryContinueDrag event enables the drag source to declare whether the drag-and-drop operation should be canceled.

此事件创建此类的 DragDrop.PreviewQueryContinueDrag 附加事件的别名,以便在将 UIElement 作为基元素继承时,PreviewQueryContinueDrag 是类成员列表的一部分。This event creates an alias for the DragDrop.PreviewQueryContinueDrag attached event for this class, so that PreviewQueryContinueDrag is part of the class members list when UIElement is inherited as a base element. 附加到 PreviewQueryContinueDrag 事件的事件处理程序附加到基础 DragDrop.PreviewQueryContinueDrag 附加事件,并接收相同的事件数据实例。Event handlers that are attached to the PreviewQueryContinueDrag event are attached to the underlying DragDrop.PreviewQueryContinueDrag 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 PreviewQueryContinueDragEvent
路由策略Routing strategy 隧道Tunneling
委托Delegate QueryContinueDragEventHandler

Applies to