How can I create persistent cookies in ASP.NET? - asp.net

Question

I am creating cookies with following lines:
HttpCookie userid = new HttpCookie("userid", objUser.id.ToString());
userid.Expires.AddYears(1);
Response.Cookies.Add(userid);
Now how can I make it persistent?
If I visit the same page again after closing the browser, I'm unable to get it back.

Answer 1

Here's how you can do that.
Writing the persistent cookie.
//create a cookie
HttpCookie myCookie = new HttpCookie("myCookie");
//Add key-values in the cookie
myCookie.Values.Add("userid", objUser.id.ToString());
//set cookie expiry date-time. Made it to last for next 12 hours.
myCookie.Expires = DateTime.Now.AddHours(12);
//Most important, write the cookie to client.
Response.Cookies.Add(myCookie);
Reading the persistent cookie.
//Assuming user comes back after several hours. several < 12.
//Read the cookie from Request.
HttpCookie myCookie = Request.Cookies["myCookie"];
if (myCookie == null)
{
//No cookie found or cookie expired.
//Handle the situation here, Redirect the user or simply return;
}
//ok - cookie is found.
//Gracefully check if the cookie has the key-value as expected.
if (!string.IsNullOrEmpty(myCookie.Values["userid"]))
{
string userId = myCookie.Values["userid"].ToString();
//Yes userId is found. Mission accomplished.
}

Answer 2

Although the accepted answer is correct, it does not state why the original code failed to work.
Bad code from your question:
HttpCookie userid = new HttpCookie("userid", objUser.id.ToString());
userid.Expires.AddYears(1);
Response.Cookies.Add(userid);
Take a look at the second line. The basis for expiration is on the Expires property which contains the default of 1/1/0001. The above code is evaluating to 1/1/0002. Furthermore the evaluation is not being saved back to the property. Instead the Expires property should be set with the basis on the current date.
Corrected code:
HttpCookie userid = new HttpCookie("userid", objUser.id.ToString());
userid.Expires = DateTime.Now.AddYears(1);
Response.Cookies.Add(userid);

Answer 3

FWIW be very careful with storing something like a userid in a cookie unencrypted. Doing this makes your site very prone to cookie poisoning where users can easily impersonate another user. If you are considering something like this I would highly recommend using the forms authentication cookie directly.
bool persist = true;
var cookie = FormsAuthentication.GetAuthCookie(loginUser.ContactId, persist);
cookie.Expires = DateTime.Now.AddMonths(3);
var ticket = FormsAuthentication.Decrypt(cookie.Value);
var userData = "store any string values you want inside the ticket
extra than user id that will be encrypted"
var newTicket = new FormsAuthenticationTicket(ticket.Version, ticket.Name,
ticket.IssueDate, ticket.Expiration, ticket.IsPersistent, userData);
cookie.Value = FormsAuthentication.Encrypt(newTicket);
Response.Cookies.Add(cookie);
Then you can read this at any time from an ASP.NET page by doing
string userId = null;
if (this.Context.User.Identity.IsAuthenticated)
{
userId = this.Context.User.Identity.Name;
}

Answer 4

As I understand you use ASP.NET authentication and to set cookies persistent you need to set FormsAuthenticationTicket.IsPersistent = true
It is the main idea.
bool isPersisted = true;
var authTicket = new FormsAuthenticationTicket(
1,
user_name,
DateTime.Now,
DateTime.Now.AddYears(1),//Expiration (you can set it to 1 year)
isPersisted,//THIS IS THE MAIN FLAG
addition_data);
HttpCookie authCookie = new HttpCookie(FormsAuthentication.FormsCookieName, authTicket );
if (isPersisted)
authCookie.Expires = authTicket.Expiration;
HttpContext.Current.Response.Cookies.Add(authCookie);

Answer 5

You need to add this as the last line...
HttpContext.Current.Response.Cookies.Add(userid);
When you need to read the value of the cookie, you'd use a method similar to this:
string cookieUserID= String.Empty;
try
{
if (HttpContext.Current.Request.Cookies["userid"] != null)
{
cookieUserID = HttpContext.Current.Request.Cookies["userid"];
}
}
catch (Exception ex)
{
//handle error
}
return cookieUserID;

Answer 6

//add cookie
var panelIdCookie = new HttpCookie("panelIdCookie");
panelIdCookie.Values.Add("panelId", panelId.ToString(CultureInfo.InvariantCulture));
panelIdCookie.Expires = DateTime.Now.AddMonths(2);
Response.Cookies.Add(panelIdCookie);
//read cookie
var httpCookie = Request.Cookies["panelIdCookie"];
if (httpCookie != null)
{
panelId = Convert.ToInt32(httpCookie["panelId"]);
}