wpf-devexpress-dot-xpf-dot-diagram-dot-diagramdatabindingbehaviorbase-6506aef8.md
Fires before generating a diagram item representing a data object and allows you to customize it.
Namespace : DevExpress.Xpf.Diagram
Assembly : DevExpress.Xpf.Diagram.v25.2.dll
NuGet Package : DevExpress.Wpf.Diagram
public event EventHandler<DiagramGenerateItemEventArgs> GenerateItem
Public Event GenerateItem As EventHandler(Of DiagramGenerateItemEventArgs)
The GenerateItem event's data class is DevExpress.Xpf.Diagram.DiagramGenerateItemEventArgs.
By default, the uppermost diagram item defined in XAML within the DiagramDataBindingBehaviorBase.TemplateDiagram is used as the template for the diagram items representing data objects.
You can use the GenerateItem event to implement custom logic for choosing the item template. To do this, create diagram items in the DiagramDataBindingBehaviorBase.TemplateDiagram and specify their names using the DiagramItem.TemplateName property. Specify the name of the desired template as the event’s CreateItemFromTemplate method parameter and assign the method return value to the event’s Item property. See the example below.
private void DiagramDataBindingBehavior_GenerateItem(object sender, DiagramGenerateItemEventArgs e) {
if (e.DataObject is PentagonDataItem)
e.Item = e.CreateItemFromTemplate("PentagonShape");
else e.Item = e.CreateItemFromTemplate("DefaultItem");
}
Private Sub DiagramDataBindingBehavior_GenerateItem(ByVal sender As Object, ByVal e As DiagramGenerateItemEventArgs)
If TypeOf e.DataObject Is PentagonDataItem Then
e.Item = e.CreateItemFromTemplate("PentagonShape")
Else
e.Item = e.CreateItemFromTemplate("DefaultItem")
End If
End Sub
Alternatively, you can use the DiagramDataBindingBehaviorBase.ItemTemplateSelector property.
The following code snippet (auto-collected from DevExpress Examples) contains a reference to the GenerateItem 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.
<dxmvvm:Interaction.Behaviors>
<dxdiag:DiagramDataBindingBehavior ItemsSource="{Binding ClassSource}" ConnectorsSource="{Binding ConnectionSource}" ConnectorFromMember="ConnectedFrom" ConnectorToMember="ConnectedTo" KeyMember="ClassName" LayoutKind="Sugiyama" ClearExistingItems="False" GenerateItem="DiagramDataBindingBehavior_GenerateItem" GenerateConnector="DiagramDataBindingBehavior_GenerateConnector">
<dxdiag:DiagramDataBindingBehavior.TemplateDiagram>
#line 13 "..\..\..\MainWindow.xaml"
((DevExpress.Xpf.Diagram.DiagramDataBindingBehavior)(target)).GenerateItem += new System.EventHandler<DevExpress.Xpf.Diagram.DiagramGenerateItemEventArgs>(this.DiagramDataBindingBehavior_GenerateItem);
#ExternalSource("..\..\..\MainWindow.xaml",13)
AddHandler CType(target,DevExpress.Xpf.Diagram.DiagramDataBindingBehavior).GenerateItem, New System.EventHandler(Of DevExpress.Xpf.Diagram.DiagramGenerateItemEventArgs)(AddressOf Me.DiagramDataBindingBehavior_GenerateItem)
See Also
DiagramDataBindingBehaviorBase Class