How to Programmatically add CSS Stylesheet file to Asp.Net page?

Sometimes its 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.

Here is how to do it, just add this code to the Page_Init event handler on the Page where you want to insert CSS file:

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

    }


And thats it, next time you load this page, reference to your CSS file will be added at runtime to the page HTML code and loaded.