wpf-devexpress-dot-xpf-dot-gantt-dot-ganttview-7480b5bf.md
Occurs when an end user edits a task’s successor and moves a connector over a new successor and allows you to display available interactive editing actions. This is a routed event.
Namespace : DevExpress.Xpf.Gantt
Assembly : DevExpress.Xpf.Gantt.v25.2.dll
NuGet Package : DevExpress.Wpf.Gantt
public event EventHandler<QueryAllowPredecessorEditEventArgs> QueryAllowPredecessorEdit
Public Event QueryAllowPredecessorEdit As EventHandler(Of QueryAllowPredecessorEditEventArgs)
The QueryAllowPredecessorEdit event's data class is QueryAllowPredecessorEditEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| Handled | Gets or sets a value that indicates the present state of the event handling for a routed event as it travels the route. Inherited from RoutedEventArgs. |
| Node | Gets the currently processed task. |
| OriginalSource | Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. Inherited from RoutedEventArgs. |
| Predecessor | Gets the currently processed task’s predecessor. |
| RoutedEvent | Gets or sets the RoutedEvent associated with this RoutedEventArgs instance. Inherited from RoutedEventArgs. |
| Source | Gets or sets a reference to the object that raised the event. Inherited from RoutedEventArgs. |
| VisibleConnectorThumbKind | Gets or sets a value that identifies which of the connector thumbs are visible for an end user. |
The event data class exposes the following methods:
| Method | Description |
|---|---|
| InvokeEventHandler(Delegate, Object) | When overridden in a derived class, provides a way to invoke event handlers in a type-specific way, which can increase efficiency over the base implementation. Inherited from RoutedEventArgs. |
| OnSetSource(Object) | When overridden in a derived class, provides a notification callback entry point whenever the value of the Source property of an instance changes. Inherited from RoutedEventArgs. |
When an end user drags a connector over a Gantt task’s node, the GanttControl displays the successor task thumbs that allow end users to understand which interactive actions are available.
The QueryAllowPredecessorEdit event is raised each time an end user moves a connector to a new potential successor.
The Interactive Editing topic describes the availability of interactive editing actions. Use the QueryAllowPredecessorEdit event to control the availability of interactive editing actions for each task individually.
See Also