This article takes a closer look at the various templates used in certain Web server controls, and how you can customize templates to enhance the look and functionality of data-bound list controls, in particular the Repeater, DataList, and DataGrid controls.
A template is basically a representation of page elements that describes the layout for a given portion of a control.
A Repeater, DataList, and DataGrid control is actually composed of heterogeneous portions called items. Each control can have five basic item types: a header, normal data items, alternating data items, separators, and a footer. In addition, the DataList and the DataGrid can have two other item types: the currently selected item, and the item that is currently being edited. Lastly, the DataGrid can also have a pager item.
Basically, you can define templates for each of the different item types that can make up a control ( headertemplate, itemtemplate, footertemplate, and so on ). The way these items are rendered is completely determined by how you implement the control’s templates.
Each template can consist of literal text, HTML elements, and/or other ASP.NET server controls that can, in the case of data items, be bound to a data source. The following examples illustrate basic use of templates.
NOTE: Templates differ from styles. Styles specify the appearance of elements such as font, color, border and so on within a control’s layout. You can use styles without using templates, if all you need to do is change the appearance of the default rendering of a control. You can also use styles with a template to control the appearance of elements that you define within your templates.