This is a TreeListView, running in virtual mode. the data is never stored within the control.
Latest Tree View Articles
Thanks to ASP.NET 2.0's built-in TreeView control, you can give your Web site a professional-looking navigation system that displays hierarchical data—without having to write lots of code and script.
Learn to get around the limitation for the maximum value of the .NET TreeView's ItemHeight property.
Latest CodeGuru Developer Columns
Learn more about a few commonly used components and explore their utility and usages.
Make a RESTful call from a UWP app to the Azure management API, the same API the portal uses, to start and stop an app service.
Using VB Namespaces can help tremendously in achieving your goal of keeping your code organized.