Load css dynamically in asp.net?

Question

I\'m creating a content management system where a user can select a css file from their server and the application will parse and store the css. The application will need t

Answer 1

I think NullReference gave you a MVC solution because you tagged your post "mvc". If you're using ASP.NET Web forms, you can use the same technique used when generating CSS-links on-the-fly on user-controls. On the page's Page_Init event, do something like the following (in the example below, I'm linking to jquery-ui-CSS):

protected void Page_Init(object sender, EventArgs e)
{
     System.Web.UI.HtmlControls.HtmlLink jqueryUICSS;
     jqueryUICSS = new System.Web.UI.HtmlControls.HtmlLink();
     jqueryUICSS.Href = "styles/jquery-ui-1.8.13.custom.css");
     jqueryUICSS.Attributes.Add("rel", "stylesheet");
     jqueryUICSS.Attributes.Add("type", "text/css");
     Page.Header.Controls.Add(jqueryUICSS);
}

If you want actual elements to be rendered on the header, then use HtmlGeneric control instead of HtmlLink in my example above. It's still the same technique--on Page_Init, add to the Page.Header.Controls collection:

    protected void Page_Init(object sender, EventArgs e)
    {
        System.Web.UI.HtmlControls.HtmlGenericControl mystyles;
        mystyles = new System.Web.UI.HtmlControls.HtmlGenericControl();
        mystyles.TagName = "style";
        string sampleCSS = "body { color: Black; } h1 {font-weight: bold;}";
        mystyles.InnerText = sampleCSS;
        Page.Header.Controls.Add(mystyles);
    }

Answer 2

Make a controller which serves the CSS content:

<link rel="stylesheet" href="@Url.Action("GetCss", "Serve", new {id="filename"})" />

Controller code:

public class ServeController: Controller
{
    public ContentResult GetCss(string id)
    {
        string cssBody = GetCssBodyFromDatabase(id);
        return Content(cssBody, "text/css");
    }
}

Answer 3

A good approach for a WebForms-only project is to link to an .ashx handler in your page instead of a static CSS file:

<link rel="stylesheet" type="text/css" href="DynamicStyles.ashx" />

Then create the handler (add a 'Generic Handler' item from Visual Studio) and within it you can load the CSS from a database or wherever. Just make sure you set the content type correctly in the handler, so that browsers recognise the response as a valid stylesheet:

context.Response.ContentType = "text/css";