How do you clear cookies using asp.net mvc 3 and c#?

Question

Ok, so I really think I am doing this right, but the cookies aren't being cleared.

 Session.Clear();
 HttpCookie c = Request.Cookies["MyCookie"];
 if (c != null)
 {
     c = new HttpCookie("MyCookie");
     c["AT"] = null;
     c.Expires = DateTime.Now.AddDays(-1);
     Request.Cookies.Add(c);
 }

 return RedirectToAction("Index", "Home");

When the redirect happens, it finds the cookie again and moves on as though I never logged out. Any thoughts?

score 107 · Accepted Answer · answered Feb 25 '11 at 21:03

107

You're close. You'll need to use the Response object to write back to the browser:

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

More information on MSDN, How to: Delete a Cookie.

answered Feb 25 '11 at 21:03

Metro Smurf

37,266
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9

Bah! Can't believe I got Response and Request mixed up. Thanks for your help! David – David Feb 25 '11 at 21:14
anything new in 2017 ? – Vikas Rana Jul 22 '17 at 06:12
3

@VikasRana Self driving cars are a big deal nowadays. – Uwe Keim Sep 25 '17 at 12:28
1

@UweKeim Thanks a lot, I didn't know about this :p – Vikas Rana Sep 26 '17 at 05:21

score 9 · Answer 2 · answered Feb 25 '11 at 20:50

Cookies are stored on the client, not on the server, so Session.Clear won't affect them. Also, Request.Cookies is populated by IIS and given to your page with each request for a page; adding/removing a cookie from that collection does nothing.

Try performing a similar action against Response.Cookies. That should cause your client to overwrite the old cookie with the new one, causing it to be expired.

Alex · Answer 3 · 2012-05-16T12:51:48.953

I did this and it worked for clearing (not deleting) a session cookie:

HttpContext.Response.Cookies.Set(new HttpCookie("cookie_name"){Value = string.Empty});

Based on Metro's response I created this extension method to make the code reusable in any controller.

/// <summary>
/// Deletes a cookie with specified name
/// </summary>
/// <param name="controller">extends the controller</param>
/// <param name="cookieName">cookie name</param>
public static void DeleteCookie(this Controller controller, string cookieName)
{
    if (controller.HttpContext.Request.Cookies[cookieName] == null)
            return; //cookie doesn't exist

    var c = new HttpCookie(cookieName)
                {
                    Expires = DateTime.Now.AddDays(-1)
                };
    controller.HttpContext.Response.Cookies.Add(c);
}

tried several things with only having AuthorizationContext and your solution finally worked — CodingYourLife, Dec 22 '14 at 01:47

How do you clear cookies using asp.net mvc 3 and c#?

3 Answers3

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