asp.net 操作cookie的简单实例

 protected void page_load(object sender, eventargs e)
    {
        if (!ispostback)
        {
            httpcookie cookie = request.cookies["logininfo"];

            if (cookie != null)
            {
                cb_repwd.checked = true;
                tb_loginname.text = uihelper.decrypt(cookie["loginname"]);
                tb_pwd.attributes.add("value", uihelper.decrypt(cookie["pwd"]));
            }
            else
            {
                tb_pwd.attributes.add("value", "******");
            }

        }

    }

    protected void btn_login_click(object sender, eventargs e)
    {

        if (uihelper.getstring(session["code"]).toupper()!=this.tb_code.text.trim().toupper())
        {
            ojavascript.alert("验证码输入不正确");
            return;
        }

        netuserservice nerservice = contextfactory.getobject<netuserservice>("netuserservice");
        string sql = string.format("from netuser where loginname='{0}'", tb_loginname.text.trim());
        ilist<netuser> list = nerservice.find(sql);
        if (list.count > 0)
        {
            if (list[0].status == 2)
            {
                ojavascript.alert("帐号已停用，请联系管理员");
                return;
            }
        }

        if (nerservice.login(tb_loginname.text.trim(), osecurity.getpwdencrypt(tb_pwd.text.trim())))
        {
            httpcookie cookie = request.cookies["logininfo"];
            if (cb_repwd.checked)
            {
                if (cookie == null)
                {
                    httpcookie cookielogin = new httpcookie("logininfo");
                    setcookies(cookielogin,7);
                }
                else
                {
                    if (uihelper.decrypt(request.cookies["logininfo"]["loginname"]) != tb_loginname.text.trim())
                    {
                        setcookies(cookie, 7);
                    }
                }
            }
            else
            {
                setcookieexpires(cookie);
            }

           
            ojavascript.redirect("/");
        }
        else
        {
            ojavascript.alert( "用户名或密码不正确");
        }
    }

    #region cookie
    /// <summary>
    /// 设置cookie
    /// </summary>
    /// <param name="cookielogin">httpcookie cookielogin</param>
    /// <param name="expires">有效期</param>
    private void setcookies(httpcookie cookielogin, int expires)
    {
        cookielogin.values["loginname"] = uihelper.encrypt(tb_loginname.text.trim());
        cookielogin.values["pwd"] = uihelper.encrypt(tb_pwd.text.trim());
        cookielogin.expires = datetime.now.adddays(expires);
        response.appendcookie(cookielogin);
    }

    /// <summary>
    /// 设置cookie失效
    /// </summary>
    /// <param name="cookielogin">httpcookie cookielogin</param>
    private void setcookieexpires(httpcookie cookielogin)
    {
        if (cookielogin != null)
        {
            cookielogin.expires = datetime.now.adddays(-1); ;
            response.appendcookie(cookielogin);
        }
    }
    #endregion

设置cookie过期其实就是修改cookie，必须重新向客户端发送cookie

request.cookies取cookie, response，cookies添加cookie

虽然简单，但是不太了解的还是很容易出错