>Yes, my treeview is populated with data from a table called,lets say, "companies",and the companies have different type (investment managers, sponsors , consultants). My question is : depending on the tab I am (companies, managers,sponsors) i wanna see in treeview only the companies which match that criteria.

First off, from what you've described, it sounds like a TreeView isn't your best solution in this case. If you are only using one table to populate the TreeView, I would just use a listbox. A TreeView is usually used to show hierarchical relationships, or 1-to-many relations. Using a ListBox would be quicker in this case (a non-hierarchical relationship view).

But using your TreeView, it partly depends on how you are populating it. Is each "main" node a company type? Then each type node has child nodes that represent the companies?

In any case...

> Does collapsing prevent displaying?

No. You'd have to program that functionality, to prevent the user to expanding a node if you didn't want them to.

> Also I can use 3 treeviews, being one for each criteria , one on top of another, and set their visible property to false or true when necessary. Is that going to make my program slower than in the first case?

That sounds like your best solution if you are dealing with hundreds of records for each different criteria. I'd populate each treeview when the form loads, then change their ZOrder to display the one you want.

Hope that helps,

jody