TreeView Drawing

Answer 1

There are be several ways to go about this:

• Write it yourself (it's rather easy to do if you know the type of diagrams you're dealing with and customization is not important)
• Automate one of the well-known applications which do that (Visio or Omnigraffle come to mind). In fact, when I had to programmatically generate manipulate diagrams like that, I ended up writing .NET code inside Visio.
• Look through open-source UML tools to see if there is code you can use. A good list of such tools can be found on Wikipedia. Please pay attention to the license of the code you end up using.