Un tema es un conjunto de configuraciones que definen la apariencia de las páginas y controles en una aplicación web, permitiendo que se aplique solo uno por página. Los temas pueden ser globales, afectando a todos los sitios en un servidor, y están compuestos por elementos como skins, hojas de estilo CSS e imágenes. Su uso simplifica la gestión de estilos, ya que permite aplicar propiedades de forma uniforme en todos los controles o páginas de la aplicación.

2.  A theme is a collection of property setting
that allow you to define the look of pages and
controls in web application.
 We can apply theme in one or more pages in
web application.
 Only one theme can be applied to each page .
You cannot apply multiple themes to a page

3.  Themes are made up of a set of elements :
skins,cascading style sheets(CSS),images etc.
 Themes are defined in special directories in
your website.

4.  A global theme is a theme that you can apply
to all the web sites on a server.
 Global themes allow you to define an overall
look for your domain when you maintain
multiple web sites on the same server.
 The content of a theme is the same whether
the theme is defined as a page theme or as a
global theme.

5.  To style them with CSS alone, you'll have to
set loads of properties on each one: DayStyle
and TitleStyle and NextPrevStyle and on and
on...
 Using a theme will allow you to set all of
those properties just once, and have it apply
to every control or page.

6.  In the Solution Explorer, right-click on the
web site name and point to Add ASP.NET and
click Themes.
 Visual Studio will create a App_Themes folder
automatically.
 Create a subfolder of the App_Themes folder
and name it accordingly.
 Add Skins, Cascading Style
Sheets, and Images as needed.

7. First Way is:-
 In the application's web.config file, set
the <pages> element to the name of the
theme, either page or global.
<configuration>
<system.web>
<pages theme="ThemeName" />
</system.web>
</configuration>

8.  Set a style sheet theme to be subordinate to
the local control properties, and set
the styleSheetThemeattribute instead.
<configuration>
<system.web>
<pages styleSheetTheme="ThemeName" />
</system.web>
</configuration>

9.  Set the Theme or StyleSheetTheme attribute
of the @Page directive to the name of the the
<%@ Page Theme="ThemeName" %>
<%@ Page StyleSheetTheme="ThemeName"
%> me.

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