C1TreeView supports UI virtualization for hierarchical data. Virtualization is an optimization to avoid constructing and rendering the container objects for items that are not visible. When the virtualization is enabled for C1TreeView it creates only the treeview items needed to display the items that are visible on screen. For example, suppose we have a C1TreeView with 10,000 items, but only 50 are visible at any time.Without virtualization, the C1TreeView would take a long time to render 10,000 treeview items even though only 50 treeview items are visbile.With virtualization the C1TreeView would only create what is needed to display in this case only 50 treeview items. As a result, using virtualization when needed would improve performance.

The UI Virtualization is disabled in C1TreeView, by default. To enable it you can use the following markup:

<TreeView VirtualizingStackPanel.IsVirtualizing="True" … />