I am creating a virtual TreeList and have handlers for the the VirtualModeCreateChildren and VirtualModeNodeCreating events. Everything works great when I create the top level. When you try to expand one of the top level items the handler for the VirtualModeCreateChildren event fires and calls the appropriate function.  However the EventArgs is null and the sender object doesn't contain any information as to which object is the parent object.

How do you find the parent object when expanding the treelist?

Hi,

It sounds weird that the EventArgs is null.
Could you please upload a project that demonstrates this behavior?

I'm getting the same null args here. What is the status of this issue?

LOL, looks like it fires VirtualModeCreateChildren event for each level, that's why...

Resolved. Disregard.

Hello, I've same (I guess) issue and thus general question about how  VirtualMode works.  

So, for me, when user expands any node,  and server event is fired - TreeView loses its info on all nodes. Its empty. And then it rebuilds all nodes from the root, including new elements in last expanded node.

Is that a correct behavior ?

The same here.

It´s wired... What´s the point of the visual mode if the tree is constructed from the scratch everytime the user interacts with it? (even when he selects a node)

I´m storing all nodes I have created in the session now, that solves the problem in a way.

But like Nick said: "Is that a correct behavior ?"

Nick Walkovskiy:

Is that a correct behavior ?

Can we have an answer on this, please ?

Hi Nick,

Yes, this behavior is by design. We decided not to store nodes in the ViewState. Nodes must be re-created every time the page is reloaded.
Of course, sometimes it is expensive to create nodes every time. In this case you may easily cache them in the ViewState / SessionState using the key->value hashtable.