我认为没有一种自动化的方法可以实现这一目标。我认为最好的方法是向身份验证 cookie 添加一个日期,这将是您最后一次检查用户是否存在。因此,当用户登录时,您将:
FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(
1, // Ticket version
name, // Username associated with ticket
DateTime.Now, // Date/time issued
DateTime.Now.AddMonths(1), // Date/time to expire
true, // "true" for a persistent user cookie
DateTime.Now.ToUniversalTime(), // last time the users was checked
FormsAuthentication.FormsCookiePath);// Path cookie valid for
// Encrypt the cookie using the machine key for secure transport
string hash = FormsAuthentication.Encrypt(ticket);
HttpCookie cookie = new HttpCookie(
FormsAuthentication.FormsCookieName, // Name of auth cookie
hash); // Hashed ticket
cookie.HttpOnly = true;
// Set the cookie's expiration time to the tickets expiration time
if (ticket.IsPersistent) cookie.Expires = ticket.Expiration;
//cookie.Secure = FormsAuthentication.RequireSSL;
Response.Cookies.Add(cookie);
然后,每次对用户进行身份验证时,您都可以检查传递给身份验证票证的附加日期,并以 10 分钟或更短的时间间隔再次检查数据库是否存在用户。代码可能如下所示:
public void FormsAuthentication_OnAuthenticate(object sender,
FormsAuthenticationEventArgs args)
{
if (FormsAuthentication.CookiesSupported)
{
if (Request.Cookies[FormsAuthentication.FormsCookieName] != null)
{
try
{
FormsAuthenticationTicket ticket = FormsAuthentication.Decrypt(
Request.Cookies[FormsAuthentication.FormsCookieName].Value);
DateTime lastCheckedTime = DateTime.TryParse(ticket.UserData);
TimeSpan elapsed = DateTime.Now - lastCheckedTime;
if (elapsed.TotalMinutes > 10)//Get 10 from the config
{
//Check if user exists in the database.
if (CheckIfUserIsValid())
{
//Reset the last checked time
// and set the authentication cookie again
}
else
{
FormsAuthentication.SignOut();
FormsAuthentication.RedirectToLoginPage();
return;
}
}
}
catch (Exception e)
{
// Decrypt method failed.
}
}
}
}
您甚至可以缓存在过去 10 分钟内被删除的用户并检查该集合。
希望有帮助。