Binding Dropdownlist with full path like in Treeview

 <asp:DropDownList ID="ddclient" runat="server" Width="125px" >
                                        </asp:DropDownList>


  <table>
                    <tr>
                        <td valign="top" align="left">
                            <asp:TreeView ID="treeClient" runat="server" Visible="False">
                            </asp:TreeView>
                        </td>
                        <td valign="top" align="left">
                            <asp:DropDownList ID="DropDownListTree" runat="server" Visible="False">
                            </asp:DropDownList>
                        </td>
                    </tr>
                </table>



Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Try
         
                If Not Page.IsPostBack Then
                    PopulateRootLevel()
                    AddNoteToCombo(treeClient.Nodes, "")
                    fillOrg4client()
                End If
        Catch ex As Exception
       
        End Try
    End Sub



Private Sub fillOrg4client()
        Dim rw As New ListItem
        ddclient.Items.Clear()

        For Each lis As ListItem In DropDownListTree.Items
            Dim sr = Replace(lis.Text, "%o", "")
            sr = Replace(sr, "%p", "")
            'If sr.Contains(cmbClient.SelectedItem.Text) Then
            '    If cmbClient.SelectedItem.Text <> sr Then
            rw = New ListItem
            rw.Text = sr
            rw.Value = lis.Value
            ddclient.Items.Add(rw)
            '    End If

            'End If
        Next
        'End If

        rw = New ListItem()
        rw.Text = "Select"
        rw.Value = -1
        ddclient.Items.Insert(0, rw)

        ddclient.SelectedValue = -1
    End Sub




Private Sub treeClient_TreeNodePopulate(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.TreeNodeEventArgs) Handles treeClient.TreeNodePopulate
        PopulateSubLevel(CInt(e.Node.Value), e.Node)
    End Sub
    Private Sub AddNoteToCombo(ByVal nc As TreeNodeCollection, ByVal str As String)
        For i As Integer = nc.Count - 1 To 0 Step -1
            Dim lst As New ListItem
            lst.Value = nc(i).Value
            str = Replace(str, "Surgere%o", "", 1, 9) 'Remove this to add surge to all
            If str = "" Then
                lst.Text = nc(i).Text
            Else

                lst.Text = str + "\" + nc(i).Text
            End If
            If Not lst.Text.Equals("Surgere%o") Then
                DropDownListTree.Items.Add(lst)
            End If

            If nc(i).ChildNodes.Count > 0 Then
                If str = "" Then
                    AddNoteToCombo(nc(i).ChildNodes, nc(i).Text)
                Else

                    AddNoteToCombo(nc(i).ChildNodes, str + "\" + nc(i).Text)
                End If

            End If
            'If nc(i).ChildNodes.Count = 0 Then

            ' End If
        Next
    End Sub

    Private Sub PopulateRootLevel()
        DropDownListTree.Items.Clear()
        Dim stBuilder As New StringBuilder()
        stBuilder.Append("select CLIENT_ID,CLIENT_NAME,o_or_p,active_yn,(select count(*) FROM client ")
        stBuilder.Append(" WHERE reports_to_id=sc.CLIENT_ID) childnodecount FROM client sc where reports_to_id=0")
        Dim selectQry = stBuilder.ToString()
        'Dim selectQry = "select CLIENT_ID,CLIENT_NAME,o_or_p,active_yn,(select count(*) FROM client " &
        '           " WHERE reports_to_id=sc.CLIENT_ID) childnodecount FROM client sc where reports_to_id=0"
        'Dim cmm As SqlCommand = New SqlCommand(selectQry)
        'Dim result As Object
        Dim dtTree = New DataTable
        dtTree = DataConnect.GetInstance.GetDt(selectQry)

        PopulateNodes(dtTree, treeClient.Nodes, "")
        treeClient.ExpandAll()
    End Sub
    Private Sub PopulateNodes(ByVal dt As DataTable, ByVal nodes As TreeNodeCollection, ByVal st As String)
        For Each dr As DataRow In dt.Rows

            Dim tn As New TreeNode()

            tn.Text = dr("client_name").ToString() ' + "<asp:ImageButton runat='server' ImageUrl='~/Images/plus.gif' onClick='clickPlus()'>"
            tn.Value = dr("client_id").ToString()
            If dr("o_or_p").ToString().Trim() = "p" Then
                tn.Text = tn.Text + "%p"


            Else
                tn.Text = tn.Text + "%o"

            End If
            tn.Target = dr("client_name").ToString()
            nodes.Add(tn)
            'DropDownListTree.Items.Add(st + ">" + tn.Text)
            'If node has child nodes, then enable on-demand populating
            tn.PopulateOnDemand = (CInt(dr("childnodecount")) > 0)
        Next
    End Sub
    Private Sub PopulateSubLevel(ByVal parentid As Integer, ByVal parentNode As TreeNode)

        Dim stBuilder As New StringBuilder()
        stBuilder.Append("select CLIENT_ID,CLIENT_NAME,o_or_p,active_yn,(select count(*) FROM client ")
        stBuilder.Append(" WHERE reports_to_id=sc.CLIENT_ID) childnodecount FROM client sc where reports_to_id=@parentID")
        Dim selectQry = stBuilder.ToString()
        'Dim selectQry = "select CLIENT_ID,CLIENT_NAME,o_or_p,active_yn,(select count(*) FROM client " &
        '      " WHERE reports_to_id=sc.CLIENT_ID) childnodecount FROM client sc where reports_to_id=@parentID"

        Dim objCommand = New SqlCommand(selectQry)
        objCommand.Parameters.Add("@parentID", SqlDbType.Int).Value = parentid
        Dim dt = New DataTable
        dt = DataConnect.GetInstance.GetDt(objCommand)
        PopulateNodes(dt, parentNode.ChildNodes, "")
    End Sub