Recently I've been asked to create a mega menu on an ASP.NET website which was using a standard ASP.NET menu control. Luckily for me I came across an article how to create a jQuery Mega Menu.

What I wanted to do is to combine the jQuery Mega Menu with standard ASP.NET menu using sitemap datasource.

Let's build a new website project from scratch so you can see clearly what you need to do to get your mega menu working with asp.net menu.

I'm going to repeat here some steps which are in the jQuery Mega Menu article

You need to download the following files and place them inside your website project.

- jkmegamenu.css - place this file in yoursite\App_Themes\Theme1\jkmegamenu.css
- jkmegamenu.js - place this file in yoursite\jscript\jkmegamenu.js
- jquery-1.3.2.min.js - place this file in yoursite\jscript\jquery-1.3.2.min.js





Step 1: Create a new master page. In the head tag you need to enter the following

<head runat="server">
<title>My Site</title>
<script type="text/javascript" src="jscript/jquery-1.3.2.min.js"></script>

<script type="text/javascript" src="jscript/jkmegamenu.js">
/***********************************************
* jQuery Mega Menu- by JavaScript Kit (www.javascriptkit.com)
* This notice must stay intact for usage
* Visit JavaScript Kit at http://www.javascriptkit.com/ for full source code
***********************************************/
</script>
</head>



Step 2: Now create a web.sitemap which will be used as our datasource for the menu.

<?xml version="1.0" encoding="utf-8" ?>
<siteMap xmlns="http://schemas.microsoft.com/AspNet/SiteMap-File-1.0" >

<siteMapNode url="~" title="Root"  description="">
<siteMapNode url="~/Default.aspx" title="Page1"  />
<siteMapNode url="~/Default2.aspx" title="Page2" >
<siteMapNode url="~/Default2_1.aspx" title="Page2_1" >
<siteMapNode url="~/Default2_1_1.aspx" title="Page2_1_1" />
<siteMapNode url="~/Default2_1_2.aspx" title="Page2_1_2" />
<siteMapNode url="~/Default2_1_3.aspx" title="Page2_1_3" />
</siteMapNode>
<siteMapNode url="~/Default2_2.aspx" title="Page2_2" >

<siteMapNode url="~/Default2_2_1.aspx" title="Page2_2_1" />
<siteMapNode url="~/Default2_2_2.aspx" title="Page2_2_2" />
<siteMapNode url="~/Default2_2_3.aspx" title="Page2_2_3" />
<siteMapNode url="~/Default2_2_4.aspx" title="Page2_2_4" />
<siteMapNode url="~/Default2_2_5.aspx" title="Page2_2_5" />
</siteMapNode>
<siteMapNode url="~/Default2_3.aspx" title="Page2_3" >
</siteMapNode>
</siteMapNode>

<siteMapNode url="~/Default3.aspx" title="Page3" >
</siteMapNode>
<siteMapNode url="~/Default4.aspx" title="Page4" >
</siteMapNode>
</siteMapNode>
</siteMap>



Step 3: Enter the following code in the master page within the form tag. Here we have our menu bound to SiteMapDataSource. We need to generate anchors ("anchorLiteral") and also html code for our mega menus ("menuLiteral"). I set the menu to fire OnDataBound event. Inside this event we can generate all the required code.

<asp:Literal ID="anchorLiteral" runat="server"></asp:Literal>
<asp:Literal ID="menuLiteral" runat="server"></asp:Literal>
<asp:Menu ID="Menu1" runat="server" StaticDisplayLevels="1" 
MaximumDynamicDisplayLevels="2" DataSourceID="SiteMapDataSource1" 
Orientation="Horizontal" OnDataBound="Menu1_DataBound">
</asp:Menu>
<asp:SiteMapDataSource ID="SiteMapDataSource1" runat="server" 
ShowStartingNode="False" />




Step 4: Now we need to write the code behind the master page. The code loops through the menu items and generates required html code and scripts to get basic menu with mega menu dropdown.

protected void Menu1_DataBound(object sender, EventArgs e)
    {
        //hide the asp menu
        Menu1.Visible = false;
        
        //holds html anchors
        anchorLiteral.Text = "";

        //holds html mega dropdown menu
        menuLiteral.Text = "";

        //register megamenu script and create anchor foreach top level

        StringBuilder mScript = new StringBuilder();
        StringBuilder anchorText = new StringBuilder();
        StringBuilder menuText = new StringBuilder();

        mScript.AppendLine(@"<script type='text/javascript'>");
        int cntLvl1 = 0;
        
        foreach (MenuItem lvl1 in Menu1.Items)
        {
            cntLvl1++;
            string anchorId = "megaanchor" + cntLvl1.ToString();
            string megamenuId = "megamenu" + cntLvl1.ToString();

            //anchor for each top level menu
            anchorText.AppendLine("<a href='" + lvl1.NavigateUrl + "' id='" +
                anchorId + "' class='topMenuCMSListMenuLinkHighlighted'>" +
                lvl1.Text + "</a>");

            //building mega menu div if menuitem has children
            if (lvl1.ChildItems.Count > 0)
            {
                int cntLvl2 = 0;
                //script for each top level menu
                mScript.Append(@"jkmegamenu.definemenu('" + anchorId + "', '" + 
                    megamenuId + "', 'mouseover');");

                menuText.AppendLine("<div id='" + megamenuId + "' class=megamenu>");
                
                //building columns within the mega menu
                foreach (MenuItem lvl2 in lvl1.ChildItems)
                {
                    cntLvl2++;
                    menuText.AppendLine("<div class='column'>");
                    menuText.AppendLine("<h3><a href='" + lvl2.NavigateUrl + "'>" + 
                        lvl2.Text + "</a></h3>");

                    //create ul list if any children
                    if (lvl2.ChildItems.Count > 0)
                    {
                        menuText.AppendLine("<ul>");
                        foreach (MenuItem lvl3 in lvl2.ChildItems)
                        {
                            menuText.AppendLine("<li><a href='" + lvl3.NavigateUrl + "'>" + 
                                lvl3.Text + "</a></li>");
                        }
                        menuText.AppendLine("</ul>");
                    }

                    menuText.AppendLine("</div>");

                    //break after 2 columns
                    if (cntLvl2 >= 2)
                    {
                        menuText.AppendLine("<br style='clear: left' />");
                        cntLvl2 = 0;
                    }
                }
                menuText.AppendLine("</div>");
            }
        }

        anchorText.AppendLine("</ul>");

        anchorLiteral.Text = anchorText.ToString();
        menuLiteral.Text = menuText.ToString();
        mScript.AppendLine(@"</script>");
        Guid gid = System.Guid.NewGuid();

        Page.ClientScript.RegisterStartupScript(this.GetType(), gid.ToString(), mScript.ToString());

    }





Now here is the result.....