Occurs before a node is collapsed and allowing the action to be canceled.
public event TreeListNodeAllowEventHandler NodeCollapsing
Public Event NodeCollapsing As TreeListNodeAllowEventHandler
The NodeCollapsing event's data class is TreeListNodeAllowEventArgs. The following properties provide information specific to this event:
|Allow||Gets or sets whether the operation is allowed.|
|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 processed node. Inherited from TreeListNodeEventArgs.|
|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.|
|Row||Gets the processed row. Inherited from TreeListNodeEventArgs.|
|Source||Gets or sets a reference to the object that raised the event. Inherited from RoutedEventArgs.|
The event data class exposes the following methods:
|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.|
To learn more, see Expanding and Collapsing Nodes .