Show Dynamic CSS : Themes « Development « ASP.NET Tutorial

<%@ Page Language="C#" Theme="DynamicSkin" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<script runat="server">

    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        grdProducts.CssClass = ddlCssClass.SelectedItem.Text;
    }
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Show Dynamic CSS</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

    <asp:GridView
        id="grdProducts"
        DataSourceID="srcProducts"
        HeaderStyle-CssClass="Header"
        AlternatingRowStyle-CssClass="Alternating"
        GridLines="none"
        Runat="server" />

    <asp:SqlDataSource
       id="srcProducts"
       ConnectionString="<%$ ConnectionStrings:Products %>"
       SelectCommand="SELECT Id,Title,Director FROM Products"
       Runat="server" />

    <hr />

    <asp:Label
        id="lblCssClass"
        Text="Select Style:"
        AssociatedControlID="ddlCssClass"
        Runat="server" />
    <asp:DropDownList
        id="ddlCssClass"
        Runat="server">
        <asp:ListItem Text="Professional" />
        <asp:ListItem Text="Colorful" />
    </asp:DropDownList>
    <asp:Button
        id="btnSubmit"
        Text="Select"
        Runat="server" OnClick="btnSubmit_Click" />

    </div>
    </form>
</body>
</html>

9.42.Themes
	9.42.1.	An ASP.NET Theme enables you to apply a consistent style to the pages.
	9.42.2.	How Themes Work
	9.42.3.	Adding Skins to Themes
	9.42.4.	Creating Named Skins with a SkinID property
	9.42.5.	Themes Versus StyleSheetThemes
	9.42.6.	Override Skin properties by applying a Theme to a page with the StyleSheetTheme attribute instead of the Theme attribute.
	9.42.7.	Disabling Themes
	9.42.8.	Adding Cascading Style Sheets to Themes
	9.42.9.	Handling Theme Conflicts
	9.42.10.	Configure specific controls so they opt out of the theming process entirely.
	9.42.11.	Share the Theme among multiple web applications running on the same web server
	9.42.12.	Applying Themes Dynamically
	9.42.13.	Applying Skins Dynamically
	9.42.14.	Show Dynamic CSS