How to Iterate TreeView Nodes Recursively

Level: Intermediate
Knowledge Required:

• Recursion
• TreeView Control

Description:
In this article we will use a code which Recursively Iterates through each TreeView Node.

Private Sub IterateTreeViewNodesRecursively(Optional ByRef ParentNode As TreeNode = Nothing)
    Dim objNodes As TreeNodeCollection

    ' if parentnode is NOT given then use treeview's nodes
    If ParentNode Is Nothing Then
        objNodes = Me.TreeView1.Nodes
    Else ' else it means parentnode is mentioned so use it's nodes
        objNodes = ParentNode.Nodes
    End If

    For Each n As TreeNode In objNodes
        ' perform your checking here
        'E.g.:
        'If n.Checked Then
        '    ' perform your operation here
        'End If
        'If n.Tag = "FOLDER" Then
        '    ' perform your operation here
        'End If
        If n.Nodes.Count > 0 Then        ' if this node has children
            ' iterate each children
            Call IterateTreeViewNodesRecursively(n)
        End If
    Next
End Sub

Note that if you want to access the checked nodes only you can use the above code but I have discussed another approach in the earlier post you can also see it.