Hi,
As your description, your trrview's currentnode's selectednodestyle cannot work with the navigateURL.Is it right?
There is a litte difference between Navigation and selection. When you select a node, it is a function of posting back to the same page. But when you click on the node with a NavigationURL, the page will redirect to a new page.
As your above said, you bind the treeview to a SiteMapDataSource, you can try to wirte some special code which can autoselect the current node. Alternatively, if you write a similar piece of code in a Load event for your TreeView, you can cause a node to become selected and your style to appear.
Hope it helps.
Please remember to mark the replies as answers if they help and unmark them if they provide no help.
Yours sincerely,
Amanda Wang
Microsoft Online Community Support