Load CSS Dynamically in ASP.Net (C# & VB.Net)

Sometimes it is necessary to programmatically add some CSS stylesheets to your ASP.Net page, for example if you want to allow your users to change look and feel of your website by choosing themes, etc.

C#

Add the following namespace in your CodeBehind

using System.Web.UI.HtmlControls;

Now bind the css dynamically from CodeBehind

protected void Page_Init(object sender, EventArgs e) {
    HtmlLink css = new HtmlLink();
    css.Href = "css/style.css";
    css.Attributes["rel"] = "stylesheet";
    css.Attributes["type"] = "text/css";
    css.Attributes["media"] = "all";
    Page.Header.Controls.Add(css);
}

VB.Net

Imports System.Web.UI.HtmlControls

Protected Sub page_init(ByVal sender As Object, ByVal e As EventArgs)
   Dim css As New HtmlLink()
   css.Href = "css/style.css"
   css.Attributes("rel") = "stylesheet"
   css.Attributes("type") = "text/css"
   css.Attributes("media") = "all"
   Page.Header.Controls.Add(css)
End Sub