ASP.NET 3.5 For Dummies®

13.1. Understanding Templated Controls

Templated controls let you insert custom text, markup, styles, and other ASP.NET controls into a control's basic framework. While altering the appearance and function, you still take advantage of the control's built-in ability to bind to data and loop through items.

Templates are modular elements in that the databound control swaps template sections in and out according to its needs. For example, when the control needs to accept user input, it displays a specialized editing template.

For brevity, the instructions in this chapter don't validate user input or cover performance-enhancing AJAX. (See Chapter 19 for more on validation; Chapters 4 and 15 talk more about AJAX.)

13.1.1. Repeating yourself with the Repeater

The ASP.NET Repeater control is the least-complicated templated control. In Listing 13-1, you see its template names, such as <HeaderTemplate>, <ItemTemplate>, and <SeparatorTemplate>. Your job is to put HTML markup inside the template areas. For example, the markup within the <SeparatorTemplate> is the horizontal rule (<hr />).

If a template name has the word Item in it, it usually repeats for each item of data. For the rule to hold, <SeparatorTemplate> should be <Separator ItemTemplate>.

Listing 13-1. Template Markup for a Barebones ...