AjaxControlToolkit.PersistentStoreManager.FileExists C# (CSharp) Метод

        public bool FileExists(string controlId)
        {
            if(String.IsNullOrEmpty(controlId))
                throw new ArgumentException("controlId cannot be empty", "controlId");

            var currentContext = GetCurrentContext();
            if(currentContext == null)
                return false;

            if(currentContext.Session[GetFullID(controlId)] == null)
                return false;

            return currentContext.Session[GetFullID(controlId)] as HttpPostedFile != null;
        }