private void SendMail(User u, UserValidate uv)
{
string link = string.Format("http://{0}{1}", HttpContext.Current.Request.Url.Authority,
UrlTo <UserController>(p => p.Active(uv.SerializeToString())));
string mail = string.Format("请点击以下链接或复制链接到浏览器里以完成用户注册：<br/>\n<a href=\"{0}\">{0}</a>", link);
CommonHelper.SendMail(u.Email, mail);
}