更改已存在的 cookie 的 cookie 值 [英] Change a cookie value of a cookie that already exists

问题描述

我有一个名为 SurveyCookie 的 cookie.像这样创建:

I have a cookie called SurveyCookie. Created like so:

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，当我想像这样更改surveyPage"值时，问题就来了.

Which works great. Now the problem comes when I want to change the value "surveyPage" like so.

下面将创建一个新的 cookie，这不是我想要的.

The below will create a new cookie which is not what I want.

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，但它也不起作用.当应该是 2 时，surveyPage 仍然是 1.

Then I tried this code below which doesn't work either. The surveyPage is still 1 when it should be 2.

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

由于以上两种方法都不起作用，什么会改变surveyPage 的cookies 值?

Since neither of the above works what does change the cookies value for surveyPage?

推荐答案

来自 ASP.NET Cookie 概述:

您不能直接修改 cookie.相反，更改 cookie包括创建一个具有新值的新 cookie，然后发送cookie 到浏览器以覆盖客户端上的旧版本.

You cannot directly modify a cookie. Instead, changing a cookie consists of creating a new cookie with new values and then sending the cookie to the browser to overwrite the old version on the client.

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);

这篇关于更改已存在的 cookie 的 cookie 值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！