ASP.Net WebAPI Return CSS

Using the answers here as inspiration. You should be able to do something as simple as this:

public HttpResponseMessage Get()
{
    string css = @"h1.basic {font-size: 1.3em;padding: 5px;color: #abcdef;background: #123456;border-bottom: 3px solid #123456;margin: 0 0 4px 0;text-align: center;}";
    var response = new HttpResponseMessage(HttpStatusCode.OK);
    response.Content = new StringContent(css, Encoding.UTF8, "text/css");
    return response;
}

Can you return a HttpResponseMessage, get the file and just return the stream? Something like this seems to work....

    public HttpResponseMessage Get(int id)
    {
        var dir = HttpContext.Current.Server.MapPath("~/content/site.css"); //location of the template file
        var stream = new FileStream(dir, FileMode.Open);
        var response = new HttpResponseMessage
            {
                StatusCode = HttpStatusCode.OK, 
                Content = new StreamContent(stream)
            };

        return response;
    }

Although I would add some error checking in there if the file doesn't exist etc....

And just to pile on for fun, here's a version that would work under self-host too assuming you store the .css as an embedded file that sits in the same folder as the controller. Storing it in a file in your solution is nice because you get all the VS intellisense. And I added a bit of caching because chances are this resource isn't going to change much.

  public HttpResponseMessage Get(int id)
    {

        var stream = GetType().Assembly.GetManifestResourceStream(GetType(),"site.css");

        var cacheControlHeader = new CacheControlHeaderValue { MaxAge= new TimeSpan(1,0,0)};

        var response = new HttpResponseMessage
            {
                StatusCode = HttpStatusCode.OK, 
                CacheControl = cacheControlHeader,
                Content = new StreamContent(stream, Encoding.UTF8, "text/css" )
            };

        return response;
    }

For anyone using AspNet Core WebApi you can simply do it like this

 [HttpGet("custom.css")]
 public IActionResult GetCustomCss()
 {
     var customCss = ".my-class { color: #fff }";

     return Content(customCss, "text/css");
 }