DiagramControl.ItemsChanged Event
Fires each time an item is added or removed from the diagram.
Namespace: DevExpress.Xpf.Diagram
Assembly: DevExpress.Xpf.Diagram.v20.2.dll
NuGet Packages: DevExpress.WindowsDesktop.Wpf.Diagram, DevExpress.Wpf.Diagram
Declaration
Event Data
The ItemsChanged event's data class is DiagramItemsChangedEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| Action | Indicates whether the item is being added or removed. |
| 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. |
| Item | Returns the diagram item that is being added or removed from the diagram. |
| 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. |
Remarks
The ItemsChanged event fires whenever the DiagramControl.Items collection is modified (a document is loaded, a user performs the Undo/Redo actions, etc.).
The event parameter’s DiagramItemsChangedEventArgs.Action property indicates whether the item has been added or removed.