UIElement.PreviewQueryContinueDrag UIElement.PreviewQueryContinueDrag UIElement.PreviewQueryContinueDrag UIElement.PreviewQueryContinueDrag Event

定义

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.

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

注解

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.

此事件将为此类创建DragDrop.PreviewQueryContinueDrag附加事件的别名, 因此当继承PreviewQueryContinueDrag为基元素时UIElement , 它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 建立Tunneling
委托Delegate QueryContinueDragEventHandler

适用于