更改已存在的 cookie 的 cookie 值

Question

我有一个名为 SurveyCookie 的 cookie。像这样创建：

var cookie = new HttpCookie("SurveyCookie");
cookie.Values["surveyPage"] = "1";
cookie.Values["surveyId"] = "1";
cookie.Values["surveyTitle"] = "Definietly not an NSA Survey....";
cookie.Values["lastVisit"] = DateTime.UtcNow.ToString();
cookie.Expires = DateTime.UtcNow.AddDays(30);
Response.Cookies.Add(cookie);

效果很好。现在问题来了，当我想像这样更改值“surveyPage”时。

下面将创建一个不是我想要的新 cookie。

int cookieValue = Convert.ToInt32(Request.Cookies["SurveyCookie"]["surveyPage"]) + 1;
Response.Cookies["SurveyCookie"]["surveyPage"] = cookieValue.ToString();

然后我尝试了下面的这段代码，它也不起作用。调查页应该是 2 时仍然是 1。

Request.Cookies["SurveyCookie"]["surveyPage"] = cookieValue.ToString(); 

由于上述两种方法都不起作用，什么会改变surveyPage 的cookie 值？

Answer 1

来自ASP.NET Cookies Overview：

您不能直接修改 cookie。相反，更改 cookie 包括创建具有新值的新 cookie，然后发送 cookie 到浏览器以覆盖客户端上的旧版本。

你可以试试这个：

HttpCookie cookie = Request.Cookies["SurveyCookie"];
if (cookie == null)
{
    // no cookie found, create it
    cookie = new HttpCookie("SurveyCookie");
    cookie.Values["surveyPage"] = "1";
    cookie.Values["surveyId"] = "1";
    cookie.Values["surveyTitle"] = "Definietly not an NSA Survey....";
    cookie.Values["lastVisit"] = DateTime.UtcNow.ToString();
}
else
{
    // update the cookie values
    int newSurveyPage = int.Parse(cookie.Values["surveyPage"]) + 1;
    cookie.Values["surveyPage"] = newSurveyPage.ToString();
}

// update the expiration timestamp
cookie.Expires = DateTime.UtcNow.AddDays(30);

// overwrite the cookie
Response.Cookies.Add(cookie);

Answer 2

每次需要修改现有的 cookie 时，您都应该创建一个新的 cookie，以下对我有用：

var cookie = new System.Web.HttpCookie("SurveyCookie");
cookie.Values["surveyPage"] =  newValue;
cookie.Expires = DateTime.Now.AddDays(1000);
cookie.SameSite = System.Web.SameSiteMode.None;
cookie.Secure = true;
this.HttpContext.Response.Cookies.Add(cookie);

Answer 3

查看Response.SetCookie() 方法，因为这将设置更新您现有的cookie