Gets or sets a value that indicates whether undo support is enabled within the control (false by default). When set to true, actions performed on GanttChartItem objects within the control (either by the end user in the user interface or by code behind) are recorded to a queue and can later be undone by calling the Undo()()() method. These actions are recorded to the undo queue and can be undone: managed property value changes (Content, Indentation, IsExpanded, Start, Finish, CompletedFinish, IsMilestone, Predecessors, Item, DependencyType, AssignmentsContent, GanttChartItems, and custom properties for which AddPropertyChangeToUndoQueue(DependencyProperty, Object, Object) method is called when their values change), PredecessorItem additions and removals within Predecessors collections, GanttChartItem additions and removals in the Items collection (for Gantt Chart controls) or in the GanttChartItems collections (for Schedule Chart controls), and ScheduleChartItem additions and removals in the Items collection (for Schedule Chart controls). This is a dependency property.

public bool IsUndoEnabled { get; set; }

Public Property IsUndoEnabled As Boolean