public async Task <IHttpActionResult> ExistsEmail(string email)
        {
            JsonResult <bool> result = new JsonResult <bool>();

            if (!email.IsEmail())
            {
                result.code = 0;
                result.msg  = "邮箱格式不正确";
                return(Ok(result));
            }
            result.code   = 1;
            result.msg    = "OK";
            result.Result = await Task.Run <bool>(() => {
                bool flag           = false;
                UserInfoBll userbll = new UserInfoBll();
                flag = userbll.ExistsEmail(email);
                return(flag);
            });

            return(Ok(result));
        }