What is a Theme? How can i apply Themes to an entire application by writing code just at one place in asp.net application?

A professional and unified graphic theme as well as writing the content with a professional tone is really very imperative for businesses and can add value to the business and customers growth. Basically, a theme is a set of property settings that let you to define the appearance of pages and controls and then apply the look consistently across pages in a single Web application or across all the Web applications residing on a server.

Themes are made up of following set of elements

1.  Skins
2.  Cascading Style Sheets (CSS)
3. Images and other Resources

      Themes are defined in special directory named as “App_Themes” in your Website or on your Web server. This folder contain subfolders consist of files (such as .skin, .css and image files) that defines the appearance of web pages and controls.

Themes can be applied to a page, a web site, or globally to all the websites. Setting a theme at the Web site level applies styles and skins to all the pages and controls used in the website unless you override a theme for an individual page or control. Setting a theme at the page level applies styles and skins to that page and all its controls only.

Here are the possible ways to apply themes in asp.net:

1. In the application's Web.config file, set the <pages> element to the name of the theme, either a global theme or a page theme as shown in the following example:

<configuration>
<system.web>
<pages theme=”Write your theme name here” />
</system.web>
</configuration>

A theme setting in the Web.config file applies to all ASP.NET Web pages in that application. Theme settings in the Web.config file follow normal configuration hierarchy conventions.

2. You can set theme as a style sheet theme as given in below example:

<configuration>
<system.web>
<pages styleSheetTheme =”Write your theme name here” />
</system.web>
</configuration>

3. You can also apply a theme to an individual page. For that, set the Theme or StyleSheetTheme attribute of the @ Page directive to the name of the theme of your choice as shown in the following example:

<%@ Page Theme="ThemeName" %>

<%@ Page StyleSheetTheme="ThemeName" %>

I hope this will help you!