ASP.NET: Cookies, value not being reset, cookie not being removed

Question

I have a cookie called "g" with values "y" or "n"

I set it like this:

Response.Cookies("g").Value = "y"
Response.Cookies("g").Expires = DateTime.Now.AddHours(1)

I change it like this:

Request.Cookies("g").Value = "n"

and I try to destroy it like this

Response.Cookies("g").Expires = DateTime.Now.AddHours(-1)

The cookie gets set fine, but I cannot change its value or destroy it

Thanks!

Answer 1

Try deleting it this way:

if (Request.Cookies["g"] != null)
{
    HttpCookie myCookie = new HttpCookie("g");
    myCookie.Expires = DateTime.Now.AddDays(-1);
    Response.Cookies.Add(myCookie);
}

I think if you try creating the cookie and adding it to the Response like this it should work.

You want to add in a new cookie to the response that has the same name. Also I recommend going back a day and not just an hour.

To change the value of the cookie do this:

if (Request.Cookies["g"] != null)
{
    HttpCookie myCookie = new HttpCookie("g");
    myCookie.Expires = DateTime.Now.AddHours(1);
    myCookie.Value = "n";
    Response.Cookies.Add(myCookie);
}

The important thing to note with these examples is that we are observing the read-only request collection to see what is already in there, and then we are making changes or deleting by adding a new cookie to replace the one that was there before.

Answer 2

You cannot change the Request cookie, you can only "re-set" it in your response. Hence, you need to set the same cookie in your Response.

However the Expire-trick should work, but sometimes the DST (daylight saving time) might confuse the browser. Have you tried using a very old DateTime (like, 1970) in order to expire the cookie?