COOKIES中文乱码

cookies的中文乱码 

  //写入cookies时
  string t =HttpUtility.UrlEncode(要写入到cookies的中文值);
  HttpCookie c = new HttpCookie("user_realname", t);
  Response.Cookies.Add(c);

  //读取cookies时
  t=获取的中文cookies值;
  t = HttpUtility.UrlDecode(teacher_name);