Here is a link to the introductory to Load On Demand in RadTreeView: http://www.telerik.com/help/aspnet-ajax/tree_databindingloadondemand.html
Here is link our demos for this functionality: http://demos.telerik.com/aspnet-ajax/treeview/examples/programming/loadondemandmodes/defaultcs.aspx
If you need to ask some questions after going through these links, please feel free to contact with us again!
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