Sure, It is bit recursive, but not falling to now...
I needed that when using treenode click event and wanting to show some
contextMenu with info about selected node - because I didn't find any other built in
way to get info, if some node is selected...
That with node as argument are needed only by that with treeview,
I didn't use them stand alone...


  ''' <summary>Returns true if some node in TreeView tw is selected.</summary>
   Function HasSelectedNode (ByVal tw As TreeView ) As Boolean
     Dim i As Integer
     With tw .Nodes
       For i = 0 To . Count - 1
         If tw .Nodes . Item (i ).IsSelected Then Return True
         If HasSelectedNode (tw .Nodes . Item (i )) Then Return True
       Next
     End With
     Return False
   End Function
   ''' <summary>Returns true if some node in TreeView root node is selected.</summary>
   Function HasSelectedNode (ByVal node As TreeNode )
     Dim i As Integer
     With node .Nodes
       For i = 0 To . Count - 1
         If . Item (i ).IsSelected Then Return True
         If HasSelectedNode (. Item (i )) Then Return True
       Next
     End With
     Return False
   End Function
   ''' <summary>Returns true if some node in TreeView tw is checked.</summary>
   Function HasCheckedNode (ByVal tw As TreeView ) As Boolean
     Dim i As Integer
     With tw .Nodes
       For i = 0 To . Count - 1
         If . Item (i ).Checked Then Return True
         If HasCheckedNode (. Item (i )) Then Return True
       Next
     End With
     Return False
   End Function
   ''' <summary>Returns true if some node in TreeView root node is checked.</summary>
   Function HasCheckedNode (ByVal node As TreeNode )
     Dim i As Integer
     With node .Nodes
       For i = 0 To . Count - 1
         If . Item (i ).Checked Then Return True
         If HasCheckedNode (. Item (i )) Then Return True
       Next
     End With
     Return False
   End Function