I am attempting to use a treeview on one of my webpages. I would like to populate the nodes without a postback. I have read ll of the posts that I can find out here regarding this topic. While I have learned a lot, none have helped or totally asnswered my question.

My main question is this:  Is the javascript to call TreeView_PopulateNode SUPPOSED to be generated automatically if I set the correct, and apparently secret, series of treeview properties? OR am I responsible for writing this code? If I am responsible can someone point me to a reference that describes what I need to do.

By the way,  I have experimented with TreeView settings EnableClientScript (true/false), PopulateNodesFromClient(true/false) AND I have a server side event handler for the TreeNodePopulate Event , but I don't seem to be getting the automatically generated javascript to call TreeView_PopulateNode. I have also set the node property of PopulateOnDemand to true when I create nodes. None of this has worked.

Hopefully someone can help me. 

Kind Regards

John  

Have you seen my article about the TreeView? http://aspalliance.com/732

It demonstrates the dynamic populating (and works for sure ;-) ). Are there differences in your approach compared to mine? If you have PopulateOnDemand and PopulateNodesFromClient set, scripts to do the populating within a callback are generated automatically.

Note: You can also try using TreeView with ASP.NET Ajax.

Thanks. I will take a look. I have read so many articles on the TreeView control I could probably write a book at this point. I am beginning to think that my installation of Visual Studio has been corrupted because only part of the callback functionality is being generated automatically. Despite the fact that I have added the server side event handler for TreeNodePopulate, set the TreeView.PopulateNodesFromClient = true, and set TreeNode.PopulteOnDemand = true, I do not see the correct function and function signature being inserted into each node's html when the Tree is generated at runtime.

I want to try out the AJAX stuff but I don't want to introduce yet another variable before I get this working. I have been roling my own AJAX for quite a while so I am looking forward to a more 'standardized' way of doing asynch calls.

Thanks Teemu. I noticed in your sample code that the Treeview property ShowExpandCollapse was set to true. This property was false in my code. I changed it to true and ran the project. Just like magic the javascript to call TreeView_Populate was automatically generated. Thanks again.