VB.Net Dynamic Recursive Menu

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November 28th, 2007, 12:19 PM

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VB.Net Dynamic Recursive Menu

I got this idea from helping another member with some similar code. This uses the Menu Class to build a menu a populates it from a database, allowing for multiple child menus. Sample files are included.

Menu.aspx

Code:

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="menu.aspx.vb" Inherits="_Menu"%>
<html>
<head>
    <title>Recursive Menu Example</title>
</head>
    <body>
        <form id="Form1" runat="server">
            <asp:Panel ID="Panel1" runat="server" />
        </form>
    </body>
</html>

menu.aspx.vb

VB.Net Code:

Original - VB.Net Code

Imports System.Data.OleDb

Partial Class _Menu

Inherits System.Web.UI.Page

'//Connection to database from web.config file
    Private conn As New OleDbConnection(ConfigurationManager.ConnectionStr  ings("menu").ConnectionString)

Private Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
        Call PopulateMenu()
    End Sub

Private Sub PopulateMenu()
        Try
            '//Define new menu
            Dim menu As New Menu()

'//Retrieve menu data
 Dim menuData As DataTable = GetMenuData()
 AddTopMenuItems(menuData, menu)
 Me.Panel1.Controls.Add(menu)
 Me.Panel1.DataBind()
 Catch ex As Exception
 Response.Write(ex.Message.ToString() & " ")
 End Try
 End Sub

Private Function GetMenuData() As DataTable
        Try
            '//Populate DataTable
            Dim strSQL As String = "SELECT * FROM tbl_menu"
            Dim datMenu As OleDbDataAdapter = New OleDbDataAdapter(strSQL, conn)
            Dim tblMenu As DataTable = New DataTable()
            datMenu.Fill(tblMenu)

Return tblMenu
 Catch ex As Exception
 Response.Write(ex.Message.ToString() & " ")
 End Try 
 End Function

Private Sub AddTopMenuItems(ByVal menuData As DataTable, ByVal menu As Menu)
        Try
            '//Populate DataView
            Dim datView As DataView = New DataView(menuData)

'//Filter parent menu items
            datView.RowFilter = "parentid = 0"

'//Populate menu with top menu items
            Dim datRow As DataRowView
            For Each datRow In datView
                '//Define new menu item
                Dim parentMenu As MenuItem
                parentMenu = CreateMenuItem(datRow("linktext"), datRow("linkurl"), datRow("linktext"))
                menu.Items.Add(parentMenu)

'//Populate child items of this parent
 AddChildMenuItems(menuData, datRow("itemid"), parentMenu)
 Next
 Catch ex As Exception
 Response.Write(ex.Message.ToString() & " ")
 End Try

End Sub

Private Sub AddChildMenuItems(ByVal menuData As DataTable, ByVal parentID As Integer, Byval parentMenu As MenuItem)
        Try
            '//Populate DataView
            Dim datView As DataView = New DataView(menuData)
        
            '//Filter child menu items
            datView.RowFilter = "parentid = " & parentID

'//Populate parent menu item with child menu items
            Dim datRow As DataRowView
            For Each datRow in datView
                '//Define new menu item
                Dim childMenu As MenuItem
                childMenu = CreateMenuItem(datRow("linktext"), datRow("linkurl"), datRow("linktext"))
                parentMenu.ChildItems.Add(childMenu)

'//Populate child items of this parent
 AddChildMenuItems(menuData, datRow("itemid"), childMenu)
 Next
 Catch ex As Exception
 Response.Write(ex.Message.ToString() & " ")
 End Try
 End Sub

Private Function CreateMenuItem(ByVal strText As String, ByVal strUrl As String, ByVal strToolTip As String) As MenuItem
        Try
            '//Create new menu item
            Dim menuItem As New menuItem()

'//Set properties of the menu item
            With menuItem
                .Text = strText
                .NavigateUrl = strUrl
                .ToolTip = strToolTip
            End With

Return menuItem
 Catch ex As Exception
 Response.Write(ex.Message.ToString() & " ")
 End Try 
 End Function
End Class

 
Imports System.Data.OleDb
 
Partial Class _Menu
 
    Inherits System.Web.UI.Page
 
    '//Connection to database from web.config file
    Private conn As New OleDbConnection(ConfigurationManager.ConnectionStr  ings("menu").ConnectionString)
 
    Private Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
        Call PopulateMenu()
    End Sub
 
    Private Sub PopulateMenu()
        Try
            '//Define new menu
            Dim menu As New Menu()
 
            '//Retrieve menu data
            Dim menuData As DataTable = GetMenuData()
            AddTopMenuItems(menuData, menu)
            Me.Panel1.Controls.Add(menu)
            Me.Panel1.DataBind()
        Catch ex As Exception
            Response.Write(ex.Message.ToString() & "<br />")
        End Try
    End Sub
 
    Private Function GetMenuData() As DataTable
        Try
            '//Populate DataTable
            Dim strSQL As String = "SELECT * FROM tbl_menu"
            Dim datMenu As OleDbDataAdapter = New OleDbDataAdapter(strSQL, conn)
            Dim tblMenu As DataTable = New DataTable()
            datMenu.Fill(tblMenu)
 
            Return tblMenu
        Catch ex As Exception
            Response.Write(ex.Message.ToString() & "<br />")
        End Try        
    End Function
 
    Private Sub AddTopMenuItems(ByVal menuData As DataTable, ByVal menu As Menu)
        Try
            '//Populate DataView
            Dim datView As DataView = New DataView(menuData)
 
            '//Filter parent menu items
            datView.RowFilter = "parentid = 0"
 
            '//Populate menu with top menu items
            Dim datRow As DataRowView
            For Each datRow In datView
                '//Define new menu item
                Dim parentMenu As MenuItem
                parentMenu = CreateMenuItem(datRow("linktext"), datRow("linkurl"), datRow("linktext"))
                menu.Items.Add(parentMenu)
 
                '//Populate child items of this parent
                AddChildMenuItems(menuData, datRow("itemid"), parentMenu)
            Next
        Catch ex As Exception
            Response.Write(ex.Message.ToString() & "<br />")
        End Try
 
    End Sub
 
    Private Sub AddChildMenuItems(ByVal menuData As DataTable, ByVal parentID As Integer, Byval parentMenu As MenuItem)
        Try
            '//Populate DataView
            Dim datView As DataView = New DataView(menuData)
        
            '//Filter child menu items
            datView.RowFilter = "parentid = " & parentID
 
            '//Populate parent menu item with child menu items
            Dim datRow As DataRowView
            For Each datRow in datView
                '//Define new menu item
                Dim childMenu As MenuItem
                childMenu = CreateMenuItem(datRow("linktext"), datRow("linkurl"), datRow("linktext"))
                parentMenu.ChildItems.Add(childMenu)
 
                '//Populate child items of this parent
                AddChildMenuItems(menuData, datRow("itemid"), childMenu)
            Next
        Catch ex As Exception
            Response.Write(ex.Message.ToString() & "<br />")
        End Try
    End Sub
 
    Private Function CreateMenuItem(ByVal strText As String, ByVal strUrl As String, ByVal strToolTip As String) As MenuItem
        Try
            '//Create new menu item
            Dim menuItem As New menuItem()
 
            '//Set properties of the menu item
            With menuItem
                .Text = strText
                .NavigateUrl = strUrl
                .ToolTip = strToolTip
            End With
 
            Return menuItem
        Catch ex As Exception
            Response.Write(ex.Message.ToString() & "<br />")
        End Try        
    End Function
End Class

Table design:

This setup uses a table with the following field types:
itemid - AutoNumber
parentid - Number
linktext - Text
linkurl - Text

Parent items will have parentid = 0 whereas child items will have parentid = itemid of the parent.

Attached Files

	menu_vb.zip (8.8 KB, 127 views)
	Default1.txt (4.2 KB, 78 views)

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Last edited by mehere : February 8th, 2008 at 09:25 AM.

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