Programming Microsoft® ASP.NET 3.5

Working with Themes

For years, CSS styles have helped site developers to easily and efficiently design pages with a common and consistent look and feel. Although page developers can select the CSS file programmatically on the server, at its core CSS remains an inherent client-side technology, devised and implemented to apply skins to HTML elements. When you build ASP.NET pages, though, you mostly work with server controls.

CSS styles can be used to style server controls, but they're not the right tool for the job. The main issue here is that ASP.NET controls can have properties that are not the direct emanation of a CSS style property. The appearance of an ASP.NET control can be affected by an array of resources—images, strings, templates, markup, ...