DiagramDataBindingBehaviorBase.GenerateItem Event

Fires before generating a diagram item representing a data object and allows you to customize it.

Namespace: DevExpress.Xpf.Diagram

Assembly: DevExpress.Xpf.Diagram.v24.2.dll

NuGet Package: DevExpress.Wpf.Diagram

Declaration

C#

public event EventHandler<DiagramGenerateItemEventArgs> GenerateItem

VB.NET

Public Event GenerateItem As EventHandler(Of DiagramGenerateItemEventArgs)

Event Data

The GenerateItem event's data class is DevExpress.Xpf.Diagram.DiagramGenerateItemEventArgs.

Remarks

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.

C#

private void DiagramDataBindingBehavior_GenerateItem(object sender, DiagramGenerateItemEventArgs e) {
    if (e.DataObject is PentagonDataItem)
        e.Item = e.CreateItemFromTemplate("PentagonShape");
    else e.Item = e.CreateItemFromTemplate("DefaultItem");
}

VB.NET

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.

Related GitHub Examples

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.

XAML

wpf-diagram-use-diagramdatabindingbehavior-to-generate-diagram-from-collection/CS/DiagramDataBindingBehavior/MainWindow.xaml#L13

<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>