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Dynamic Data Loading

In an unbound mode, you need to manually create a tree (in code or XAML). A tree can be created on demand. Child nodes are dynamically created and initialized when their parent node is expanded.

To implement on demand node loading, handle the TreeListView.NodeExpanding event. This event occurs before a node is expanded, allowing you to dynamically populate its collection of child nodes. The processed node is returned by the event parameter's TreeListNodeEventArgs.Node property.

Note

When expanding a node, you do not know whether it has child nodes or not. If the node has no child nodes, hide the expand button by setting the TreeListNode.IsExpandButtonVisible property to false.

Expanded Example: How to Implement On-Demand Data Loading

Show Me

A complete sample project is available in the DevExpress Code Examples database at http://www.devexpress.com/example=E3109.

In this demo, the TreeListView displays the file/folder tree. Child nodes that correspond to sub folders or files contained within a folder are dynamically created when a parent node is being expanded.

Expanded See Also

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