ASP.NET MVC : how do I return 304 “Not Modified” status?

Question

ASP.NET MVC 3.0, IIS 7, .NET 4

I have an action that returns data that seldom changes (almost static).

Is there an easy way to:

1. return 304 \"

Answer 1

use the material provided, you can build a small utility function in your controller

protected bool CheckStatus304(DateTime lastModified)
{
    //http://weblogs.asp.net/jeff/304-your-images-from-a-database
    if (!String.IsNullOrEmpty(Request.Headers["If-Modified-Since"]))
    {
        CultureInfo provider = CultureInfo.InvariantCulture;
        var lastMod = DateTime.ParseExact(Request.Headers["If-Modified-Since"], "r", provider).ToLocalTime();
        if (lastMod == lastModified.AddMilliseconds(-lastModified.Millisecond))
        {
            Response.StatusCode = 304;
            Response.StatusDescription = "Not Modified";
            return true;
        }
    }

    Response.Cache.SetCacheability(HttpCacheability.Public);
    Response.Cache.SetLastModified(lastModified);

    return false;
}

then use it like this:

if (CheckStatus304(image.CreatedDate)) return Content(string.Empty);