C# 根据时间创建文件夹

 string file = ((fileNameIndex)index).ToString();
                    if (!Directory.Exists(HttpContext.Current.Server.MapPath("~/admin/upload/") + ((fileNameIndex)index).ToString()))
                        Directory.Exists(HttpContext.Current.Server.MapPath("~/admin/upload/") + ((fileNameIndex)index).ToString());

                    if (!Directory.Exists(HttpContext.Current.Server.MapPath("~/admin/upload/") + file + "/" + DateTime.Now.ToString("yyyy")))
                        Directory.CreateDirectory(HttpContext.Current.Server.MapPath("~/admin/upload/") + file + "/" + DateTime.Now.ToString("yyyy"));

                    if (!Directory.Exists(HttpContext.Current.Server.MapPath("~/admin/admin/upload/" + file + "/" + DateTime.Now.ToString("yyyy/MM"))))
                        Directory.CreateDirectory(HttpContext.Current.Server.MapPath("~/admin/upload/" + file + "/" + DateTime.Now.ToString("yyyy/MM")));

                    if (!Directory.Exists(HttpContext.Current.Server.MapPath("~/admin/upload/" + file + "/" + DateTime.Now.ToString("yyyy/MM/dd"))))
                        Directory.CreateDirectory(HttpContext.Current.Server.MapPath("~/admin/upload/" + file + "/" + DateTime.Now.ToString("yyyy/MM/dd")));


                    if (!Directory.Exists(HttpContext.Current.Server.MapPath("~/admin/upload/" + file + "/" + DateTime.Now.ToString("yyyy/MM/dd"))))
                        Directory.CreateDirectory(HttpContext.Current.Server.MapPath("~/admin/upload/" + file + "/" + DateTime.Now.ToString("yyyy/MM/dd")));

                    imgsrc = HttpContext.Current.Server.MapPath("~/admin/upload/" + file + "/" + DateTime.Now.ToString("yyyy/MM/dd/") + img);
                    imgsrc = "/admin/upload/" + file + "/" + DateTime.Now.ToString("yyyy/MM/dd/") + img;