'// Enum
Enum TreeNodeType
	PROJECT
	USER
	BUILD
	'// etc.
End Enum
 
'// Class
Public Class MyTreeNode
	Inherits TreeNode
	Private _TreeNodeType As TreeNodeType
 
	Public Property CurrentTreeNodeType As TreeNodeType
 
		Get
			Return _TreeNodeType
		End Get
 
		Set (Value As TreeNodeType)
			_TreeNodeType = Value
		End Set
	End Property
 
End Class
 
'// Füllen:
Projekt_id = CInt(mydatareader(0)) '
Projekt = CStr(mydatareader.Item(1)) '
tn = New TreeNode(Projekt) 'ParentNode 
tn.CurrentTreeNodeType = TreeNodeType.PROJECT

'// SelectedNodeChanged Event
Dim tn As MyTreeNode = DirectCast(TreeView.1.SelectedNode, MyTreeNode)
 
Select Case tn.CurrentTreeNodeType
	Case PROJECT : ShowProjectData
	'// etc.
End Select