asp.net mvc 验证码

 /// <summary>
        /// 生产验证码
        /// </summary>
        /// <returns></returns>
        [OutputCache(Duration = 0)]
        public ActionResult CreateCode()
        {
            string code = ValidateCodeManage.CreateValidateCode(4);
            Session["code"] = code;
            //二进制 ValidateCodeManage.CreateValidateGraphic(code)
            return File(ValidateCodeManage.CreateValidateGraphic(code), @"image/jpeg");
        }

页面上不显示验证码呢？火狐上报了个错误？
"NetworkError: 500 Internal Server Error - http://localhost:4261/Account/CreateCode" MVC 验证码 ASP.NET
[解决办法]
ActionResult 这个不对 换成哪个不记得了
[解决办法]
FileStreamResult 这个试试