缩短cookie的有效时间[MSDN]

void Application_EndRequest(Object sender, EventArgs e)
{
// Change the expiration date on outgoing persistent forms
// authentication tickets to 24 hours hence.
HttpCookie cookie1 = GetCookieFromResponse(
FormsAuthentication.FormsCookieName);
if (cookie1 != null && !String.IsNullOrEmpty (cookie1.Value))
{
FormsAuthenticationTicket ticket1 = FormsAuthentication.Decrypt(
Response.Cookies[FormsAuthentication.FormsCookieName].Value);
if (ticket1.IsPersistent)
{
FormsAuthenticationTicket ticket2 =
new FormsAuthenticationTicket (
ticket1.Version, ticket1.Name, ticket1.IssueDate,
DateTime.Now.AddHours (24), // New expiration date
ticket1.IsPersistent, ticket1.UserData,
ticket1.CookiePath
);
Response.Cookies.Remove(FormsAuthentication.FormsCookieName);
HttpCookie cookie2 = new HttpCookie(
FormsAuthentication.FormsCookieName,
FormsAuthentication.Encrypt(ticket2));
cookie2.Expires = ticket2.Expiration;
Response.Cookies.Add(cookie2);
}
}
}
HttpCookie GetCookieFromResponse (string name)
{
HttpCookieCollection cookies =
HttpContext.Current.Response.Cookies;
int count = cookies.Count;
for (int i=0; i<count; i++) {
if (String.Compare (cookies[i].Name, name, true) == 0)
return cookies[i];
}
return null;
}