ASP.NET Custom Control - What is the best way to include embedded CSS reference only once?

Question

The problem: I am embedding a CSS file into a custom control library with several controls. I want to share the same CSS file for all of the controls regardless of how many

Answer 1

I don't know why, but your solution didn't work for me, the ClientScript.IsClientScriptBlockRegistered call always returned false. But John Bledsoe's suggestion on the link you already provided (here) worked for me:

public static void IncludeStylesheet(Page page, string href, string styleID)
{
    //Prevent the stylesheet being included more than once
     styleID = "_" + styleID;
    if (HttpContext.Current.Items[styleID] == null)
    {
        HtmlLink htmlLink = new HtmlLink();
        htmlLink.Href = href;
        htmlLink.Attributes.Add("rel", "stylesheet");
        htmlLink.Attributes.Add("type", "text/css");
        page.Header.Controls.Add(htmlLink);
        HttpContext.Current.Items[styleID] = true;
    }
}