Path of TreeNode

How do I get the full path of TreeNode, all the way from the Root node?

Each TreeNode has a property ValuePath which gives the full path of TreeNode from the Root node. All node values, from the Root node, are appended with a separator. Each node value is separated by the PathSeparator attribute of TreeView control. Here is an example:

<asp:TreeView ID="tvw" runat="server" PathSeparator="\">
    <Nodes>
        <asp:TreeNode Text="C:" Value="C:">
            <asp:TreeNode Text="Abc" Value="Abc"></asp:TreeNode>
        </asp:TreeNode>
    </Nodes>
</asp:TreeView>

void tvw_SelectedNodeChanged(object sender, EventArgs e)
{
    Response.Write(tvw.SelectedNode.ValuePath);
}