//创建Cookie【防止登录信息泄露，这里使用Encode()将信息进行了加密】
    SQLHelPEr.SetCookie("NameCookie", SqlHelper.Encode(UserName), DateTime.Now.AddDays(7));
    SqlHelper.SetCookie("PwdCookie", SqlHelper.Encode(Pwd), DateTime.Now.AddDays(7));
   //获取Cookie
    string name = SqlHelper.GetCookieValue("NameCookie");
    string pwd = SqlHelper.GetCookieValue("PwdCookie");
   //删除cookie
   SqlHelper.RemoveCookie("NameCookie");
   SqlHelper.RemoveCookie("PwdCookie");  

/// <summary>
  /// 设置Cookie值和过期时间
  /// </summary>
  /// <param name="cookieName">Cookie名称</param>
  /// <param name="value">值</param>
  /// <param name="expires">过期时间</param>
  public static void SetCookie(string cookieName, string value, DateTime expires)
  {
   HttpCookie cookie = HttpContext.current.Request.Cookies[cookieName];
   if (cookie != null)
   {
    cookie.Value = value;
    cookie.Expires = expires;
    HttpContext.Current.Response.Cookies.Add(cookie);
   }
   else
   {
    cookie = new HttpCookie(cookieName);
    cookie.Value = value;
    cookie.Expires = expires;
    HttpContext.Current.Response.Cookies.Add(cookie);
   }
  }

 /// <summary>
  /// 获得Cookie的值
  /// </summary>
  /// <param name="cookieName">Cookie名称</param>
  /// <returns></returns>
  public static string GetCookieValue(string cookieName)
  {
   HttpCookie cookie = HttpContext.Current.Request.Cookies[cookieName];
   if (cookie == null)
    return "";
   else
    return cookie.Value;
  }

　　 /// <summary>
  /// 删除Cookie的值
  /// </summary>
  /// <param name="cookieName">Cookie名称</param>
  /// <returns></returns>
  public static void RemoveCookie(string cookieName)
  {
   SetCookie(cookieName, "", DateTime.Now.AddDays(1));
  }