Scott Mitchell

June 2006

Download the ASPNET_Data_Tutorial_3_CS.exe sample code.

Contents of Tutorial 3 (Visual C#)

Introduction
Step 1: Creating the Master Page
Step 2: Adding a Homepage to the Web Site
Step 2: Creating a Site Map
Step 3: Displaying a Menu Based on the Site Map
Step 4: Adding Breadcrumb Navigation
Step 5: Adding the Default Page for Each Section
Summary

Step 5: Adding the Default Page for Each Section

The tutorials in our site are broken down into different categories – Basic Reporting, Filtering, Custom Formatting, and so on – with a folder for each category and the corresponding tutorials as ASP.NET pages within that folder. Additionally, each folder contains a Default.aspx page. For this default page, let's display all of the tutorials for the current section. That is, for the Default.aspx in the BasicReporting folder we'd have links to SimpleDisplay.aspx, DeclarativeParams.aspx, and ProgrammaticParams.aspx. Here, again, we can use the SiteMap class and a data Web control to display this information based upon the site map defined in Web.sitemap.

Let's display an unordered list using a Repeater again, but this time we'll display the title and description of the tutorials. Since the markup and code to accomplish this will need to be repeated for each Default.aspx page, we can encapsulate this UI logic in a User Control. Create a folder in the website called UserControls and add to that a new item of type Web User Control named SectionLevelTutorialListing.ascx, and add the following markup:

Figure 13. Add a New Web User Control to the UserControls Folder

SectionLevelTutorialListing.ascx

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="SectionLevelTutorialListing.ascx.cs" Inherits="UserControls_SectionLevelTutorialListing" %>
<asp:Repeater ID="TutorialList" runat="server" EnableViewState="False">
    <HeaderTemplate><ul></HeaderTemplate>
    <ItemTemplate>
        <li><asp:HyperLink runat="server" NavigateUrl='<%# Eval("Url") %>' Text='<%# Eval("Title") %>'></asp:HyperLink>
                - <%# Eval("Description") %></li>
    </ItemTemplate>
    <FooterTemplate></ul></FooterTemplate>
</asp:Repeater>

SectionLevelTutorialListing.ascx.cs

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class UserControls_SectionLevelTutorialListing : System.Web.UI.UserControl
{
    protected void Page_Load(object sender, EventArgs e)
    {
        // If SiteMap.CurrentNode is not null, 
        // bind CurrentNode's ChildNodes to the GridView
        if (SiteMap.CurrentNode != null)
        {
            TutorialList.DataSource = SiteMap.CurrentNode.ChildNodes;
            TutorialList.DataBind();
        }
    }
}

In the previous Repeater example we bound the SiteMap data to the Repeater declaratively; the SectionLevelTutorialListing User Control, however, does so programmatically. In the Page_Load event handler, a check is made to ensure that this is the first visit to the page (not a postback) and that this page's URL maps to a node in the site map. If this User Control is used in a page that does not have a corresponding <siteMapNode> entry, SiteMap.CurrentNode will return null and no data will be bound to the Repeater. Assuming we have a CurrentNode, we bind its ChildNodes collection to the Repeater. Since our site map is set up such that the Default.aspx page in each section is the parent node of all of the tutorials within that section, this code will display links to and descriptions of all of the section's tutorials, as shown in the screen shot below.

Once this Repeater has been created, open the Default.aspx pages in each of the folders, go to the Design view, and simply drag the User Control from the Solution Explorer onto the Design surface where you want the tutorial list to appear.

Figure 14. The User Control has Been Added to Default.aspx

Figure 15. The Basic Reporting Tutorials are Listed