wpf-devexpress-dot-xpf-dot-controls-dot-breadcrumbcontrol-c523ae74.md
Occurs when an end user navigates to another node and allows you to cancel adding the current navigation action to the navigation history. This is a routed event.
Namespace : DevExpress.Xpf.Controls
Assembly : DevExpress.Xpf.Controls.v25.2.dll
NuGet Package : DevExpress.Wpf.Controls
public event EventHandler<BreadcrumbHistoryChangingEventArgs> HistoryChanging
Public Event HistoryChanging As EventHandler(Of BreadcrumbHistoryChangingEventArgs)
The HistoryChanging event's data class is BreadcrumbHistoryChangingEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| Cancel | Gets or sets whether the event should be canceled. Inherited from CancelRoutedEventArgs. |
| 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 breadcrumb node that is about to be added to the navigation history. |
| OriginalSource | Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. Inherited from RoutedEventArgs. |
| Reason | Gets the navigation action that caused the event firing. |
| 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. |
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. |
The BreadcrumbControl tracks the entire navigation history when the AllowFillHistory property is set to true. Use the HistoryChanging event to cancel adding a navigation action to a history.
The event arguments’ Reason property gets the navigation action kind that caused the HistoryChanging event firing. Use the HistoryNodes property to get access to a collection of recent navigation actions.
For example, you can add paths edited in the path edit box to the navigation history and ignore all the other navigation actions (like in the Windows Explorer).
See Also