Can I force a refresh of my stylesheet file?

Question

I have just spent half a day quietly going mad.

I\'m making changes to my classes in the Site.css file and they were not being reflected in the site being develope

Answer 1

To further Ian Kemp's answer which utilises the LastWriteTime of the style sheet in question, I have written an MVC helper to output the tag with the cache-busting parameter built in.

The Code

public static class CssLinkHelper
{
    public static IHtmlString StyleSheet(this HtmlHelper helper, string stylesheetname)
    {
        // define the virtual path to the css file (see note below)
        var virtualpath = "~/" + stylesheetname;
        // get the real path to the css file
        var realpath = HostingEnvironment.MapPath(virtualpath);
        // get the file info of the css file
        var fileinfo = new FileInfo(realpath);

        // create a full (virtual) path to the css file including a cache busting parameter (e.g. /main.css?12345678)
        var outputpath = VirtualPathUtility.ToAbsolute(virtualpath) + "?" + fileinfo.LastWriteTime.ToFileTime();
        // define the link tag for the style sheet
        var tagdefinition = string.Format("", outputpath);

        // return html string of the tag
        return new HtmlString(tagdefinition);
    }
}

Usage

@Html.StyleSheet("main.css")

Output

Note

In case you're wondering about the var virtualpath = "/~" + ... part and thinking, why not just pass it in as "~/main.css"? I have implemented this function this way because all my css files are in a common folder (/assets) and the helper will prefix my output with the common folder name i.e. /assets/main.css?131393346850223541