如何定义未活动玩家帐号的时间属性

       case 31: // View all inactive accounts
      {
       ArrayList results = new ArrayList();

       DateTime minTime = DateTime.Now - TimeSpan.FromDays( 90.0 );

       foreach ( Account acct in Accounts.GetAccounts() )
       {
        if ( acct.LastLogin <= minTime )
         results.Add( acct );
       }

       if ( results.Count == 1 )
        from.SendGump( new AdminGump( from, AdminGumpPage.AccountDetails_Information, 0, null, "One match found.", results[0] ) );
       else
        from.SendGump( new AdminGump( from, AdminGumpPage.Accounts, 0, results, (results.Count == 0 ? "Nothing matched your search terms." : null), new ArrayList() ) );

       break;
      }