Hi all,
I'm developing an ASP.NET web application. I'm storing information in cookies like this...

 Dim SSize2Cookie As HttpCookie
 If Request.Cookies("STACKSIZE") Is Nothing Then
      SSize2Cookie = New HttpCookie("STACKSIZE")
      SSize2Cookie.Value = CInt(1) ' integer
      Response.Cookies.Add(SSize2Cookie)
 Else ' cookie already exists
      Response.Cookies("STACKSIZE").Value = CInt(1)
 End If

After this cookie is created, I modify the cookie by overwriting it. When I attempt to modify a cookie, instead of overwriting the previous one, it creates a new one with the exact same name.

Has anyone run into this problem? Any help would be greatly appreciated.

Thanks,
Jill

I doubt this will answer your question directly but it might help in solving a cookie problem:

From my experience with web applications, it seems that cookies operate like this:
The browser sends all applicable cookies to the server with the request. These cookies are seen in the Request.Cookies collection. The Response.Cookies collection always starts out empty. If the browser doesn't receive any cookies (i.e. Response.Cookies stays empty) it doesn't do anything. Existing valid cookies in the browser stay put. When you need to send a cookie to the browser, you need to add it too the Response.Cookies collection on every page request.

You can confirm this behavior if you can watch a page in a debugger. When you look at a request that has cookies, the Response.Cookies collection will be empty to start.

Perhaps this is what's causing the conditions you are seeing.

-Peter

Thanks for your reply. I think my problem is that I was not deleting the cookie before setting a new value. After I deleted it (by setting an expiration date at a date in the past), it is working ok now.

You should be able to set a new value without deleting it. And actually, if you delete it (by adding it to Response.Cookies with an expiration date) and then adding it, you are negating the effects of the previous "delete" action. If you added then "deleted" you'd delete only because of the way the browser processes cookies.

Not sure why it took what it did to get it to work for you though.

-Peter

Hello -
I am still stuck. For some reason (I'm not sure why) I have a cookie in my web application that has not been deleted. I have put in this code to list the cookies and then set an expiration date on all those cookies (except for ASP.NET_SessionId). When the page runs, it displays the cookie to be deleted, but after the expiration date is put on the cookie (a date in the past), I expect the cookie to be immediately deleted. Unfortunately, I get a second cookie with the same name, instead of deleting it. Here's my code. Any suggestions would be great. Thanks.
Jill

Dim i
Dim aCookie As HttpCookie
For i = 0 To Request.Cookies.Count - 1
 aCookie = Request.Cookies(i)
 Response.Write("aCookie.Name: '" & aCookie.Name & "'<br>")
 If InStr(aCookie.Name, "SessionId") = 0 Then 'don't delete ASP. NET_SessionId
 ' put an expire date on it for delete
  Response.Write("ready to delete Name: '" & aCookie.Name & "'<br>")
  Response.Cookies(aCookie.Name).Expires = #1/1/2000#
 End If
Next

' now list the current cookies
 For i = 0 To Request.Cookies.Count - 1
  aCookie = Request.Cookies(i)
  Response.Write("after clean-up: aCookie.Name: '" & aCookie.Name & "'<br>")
Next
Response.End()

Jill,

Remember that the contents of Request.Cookies is what the browser has sent with the request. Any cookies in Response.Cookies are being sent back to the browser. You will not see changes in Request.Cookies until the browser has received the response and then issued another request. You need to finish one round trip and start another for cookie changes to be visible.

-Peter

Hi Peter -
OK, I did not take this into account. But, I am still having trouble. Here is my code:

If Request.Cookies("STACKSIZE") Is Nothing Then
 ' do nothing here
Else
  aCookie = Request.Cookies("STACKSIZE")
  aCookie.Expires = DateTime.Now.AddDays(-1)' delete previous cookie, if exists
  Response.Cookies.Add(aCookie) ' Response.Cookie makes a round-trip to the server. **This does not delete cookie**
End If

But, ... after this code there are now **2** Stacksize cookies.

Thanks so much for your help so far.
Jill

Um, this code will not make a round trip. You need to refresh the page after deleting the cookie.


Hal Levy
I am here to help you, not do it for you.
That is, unless you hire me. I am looking for work.

How are you determining this?

When you write a cookie to the response stream, the browser takes it and replaces any existing cookie with it. You can't have two cookies from the browser.

Perhaps an explanation of what you are attempting to accomplish with this cookie would help us understand where you having the problems. Cookies work fine for the right thing. Perhaps what you are trying to use them for could be done a different way that is more suitable.

-Peter

Hi again -
My web application that I am updating had just asp pages. The problem that I have been having is when I started rewriting some of the pages into aspx pages. No problem if a cookie is created by an aspx page and then read by an asp page. The problem occurs if an aspx page creates a cookie, then an asp page updates the cookie, then an aspx page updates the cookie, and finally an asp page tries to read this cookie. The cookie the asp page gets is the cookie value before the aspx page updated the cookie.

I now see that there are **2** cookie files created by IE: one seems to be used by the asp pages and the second by the aspx pages. So, now that I see this, I designed a work-around. The info that needs to be written by both asp and aspx pages I keep in a database. Now it seems to be working fine.

Thanks so much to all of you for your help.
Jill