The DevExpress Blazor TreeList can load child nodes when a user expands a parent node for the first time. This capability improves performance and reduces overall memory consumption when the control is bound to a large dataset. Follow the steps below to enable on-demand loading mode in the DevExpress Blazor TreeList component:

1. Assign a collection of root data items to the Data property.
2. Specify the HasChildrenFieldName property. The component uses this property to determine which nodes require expand buttons.
3. Handle the ChildrenLoadingOnDemand event. In the event handler, use the Parent argument to determine the processed node and assign the node's children to the Children event argument.

In the demo, the TreeList component uses this data binding method to display the file/folder structure of this web site.