The RadTreeView is just a visual representation of your hierarchical data. On the other hand the Index of the RadTreeViewItem shows the index of the item in its parent ( RadtreeViewitem or RadTreeView)`s Items collection. If you make any changes in the database you have to rebind the treeview in order to apply the changes. If you want your drag and drop reordering operation to reflect in the database, you have to implement your logic ( calculating the new sort Ids ( if you change them) ) and then submitting the changes in the database. Do you actually need the Index of the RadTreeViewItem in this case?
However, a blog post showing how to synchronize dnd reordering operation with the database is in our to do list and we'll do our best to have it finished for the beginning of May.
You can check related blog article here
and feel free to ask if you need further assiatance or info.
the Telerik team
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