You should set a value selected from this enumeration in the QueryContinueDragEventArgs.Action property to specify whether the framework should Cancel , Continue , or Drop the drag operation in your QueryContinueDragEventHandler . public enum DragAction { Continue = 0 , Drop = 1 , Cancel = 2 } HierarchySystem.Object System.ValueType System.Enum(System.IComparabl, System.IFormattable , System.IConvertible) DragAction Returned ByQueryContinueDragEventArgs.Action Passed ToQueryContinueDragEventArgs.{Action , QueryContinueDragEventArgs()} |