wpf-devexpress-dot-xpf-dot-navbar-dot-navigationpaneview-f1b96b01.md
Fires before the expanded state of the Navigation Pane is changed.
Namespace : DevExpress.Xpf.NavBar
Assembly : DevExpress.Xpf.NavBar.v25.2.dll
NuGet Package : DevExpress.Wpf.NavBar
public event NavPaneExpandedChangingEventHandler NavPaneExpandedChanging
Public Event NavPaneExpandedChanging As NavPaneExpandedChangingEventHandler
The NavPaneExpandedChanging event's data class is NavPaneExpandedChangingEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| Cancel | Gets or sets a value indicating whether the operation which raised an event should be canceled. |
| 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. |
| IsExpanded | Gets a value indicating whether the Navigation Pane is expanded. Inherited from NavPaneExpandedChangedEventArgs. |
| OriginalSource | Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. Inherited from RoutedEventArgs. |
| 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 NavPaneExpandedChanging event occurs when the Navigation Pane’s expanded state is going to be changed within the NavBarControl. This event allows you to cancel expanded state changing, if required.
See Also