DiagramControl.BeforeItemsMoving Event

Fires each time the end-user attempts to move a diagram item.

Namespace: DevExpress.Xpf.Diagram

Assembly: DevExpress.Xpf.Diagram.v23.2.dll

NuGet Package: DevExpress.Wpf.Diagram

Declaration

C#

public event EventHandler<DiagramBeforeItemsMovingEventArgs> BeforeItemsMoving

VB.NET

Public Event BeforeItemsMoving As EventHandler(Of DiagramBeforeItemsMovingEventArgs)

Event Data

The BeforeItemsMoving event's data class is DiagramBeforeItemsMovingEventArgs. The following properties provide information specific to this event:

Property	Description
ActionSource	Indicates whether the moving operation is performed using drag-and-drop, the Properties Panel or by pressing key shortcuts.
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.
IsCopying	Indicates whether the user attempts to copy diagram items by holding Ctrl.
Items	Returns the items the user is attempting to move.
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 event’s Items property returns the items that are about to be moved. The ActionSource property indicates whether the moving operation is performed using drag-and-drop or pressing key shortcuts. The IsCopying property returns true when the end-user attempts to move items while holding the CTRL key which results in items being copied.

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the BeforeItemsMoving event.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

XAML

wpf-diagram-track-and-restrict-drag-actions/CS/WpfApp7/MainWindow.xaml#L20

AddingNewItem="DiagramDesignerControl_AddingNewItem"
BeforeItemsMoving="DiagramDesignerControl_BeforeItemsMoving"
ItemsMoving="DiagramDesignerControl_ItemsMoving"/>