会话不会在codeigniter中被破坏

I am trying to unset my current logged in user's session.It's working fine if i am doing normal login but when i use remember me settings using cookies it's not being destroy.

My code for set the session and cookie is

public function login() {
    if(isset($this->session->userdata['username']) || isset($_COOKIE['user_id'])){
         $this->load->model('User');

            $p_uid = $this->User->user_login($_COOKIE['user_id'], $_COOKIE['password']);

     redirect(base_url() . "dashboard");
    }else{



    $this->form_validation->set_rules('user_id', 'User ID', 'required');
    $this->form_validation->set_rules('password', 'Password', 'required');
    if ($this->form_validation->run() == FALSE) {
        $this->load->view('login/login');

    } else {

        $user_id = $this->input->post('user_id');
        $password = $this->input->post('password');
        $this->load->model('User');

            $p_uid = $this->User->user_login($user_id, $password);
            //var_dump($p_uid);
            if ($p_uid) {
                if(isset($_POST['remember_me'])){
                    setcookie("user_id",$user_id,time()+86400*30);
                    setcookie("password",$password,time()+86400*30);

                }


               redirect(base_url() . "dashboard/");
            } else {
                $data=array(
                "error"=>"Wrong Userid Or Password"
                );
                $this->load->view('login/login',$data);
            }

    }
    }


}

And My logout Function is:

public function logout(){

    $this->load->helper('cookie');
    delete_cookie("user_id");
    delete_cookie("password");

    $this->session->unset_userdata("username");
    $this->session->sess_destroy();

    redirect(base_url());
}

Where i am doing mistake. please help. Thanks

I've faced the same issue a while ago. I was trying all methods which were possible. But I failed. Finally I found the solution with ob_start and ob_clean . Logout should be like this:

class controllerName extends CI_Controller
{
    function __construct()
    {
        parent::__construct();
        ob_start();
        $this->load->library('Session');
        $this->load->helper('cookie');
    }

    public function logout()
    {
        $this->load->driver('cache');   
        $user_id = array(
            'name'   => 'user_id',
            'value'  => '',
            'expire' => '0',
            'domain' => '.localhost',
            'prefix' => ''
        );

        delete_cookie($user_id);               
        $this->session->sess_destroy();
        $this->cache->clean();

        ob_clean();
        redirect(base_url());            
    }

}

To prevent browser back button previous page load, you should do something like this

$sess = $this->session->userdata('username');
if(empty($sess))
{
    $this->session->set_flashdata('error', 'Session has Expired. Please login');
    redirect('loginController/method'); 
}
else
{
    # success. 
    # continue the normal code here 
}

FYI: This should be added in every function or being used by a constructor to do it.

NOTE : Don't add password in cookie. Read - php cookie injection vulnerability?

First of all, your remember-me mechanism is seriously flawed. See Implementing Secure User Authentication in PHP Applications with Long-Term Persistence.

I don't understand how your login works. You are checking if username is set in session, then are using cookies to perform login. I guess you've made it work as the first part of || always fails since $this->session->userdata['username'] will never be set. The correct way to access username from session would be:

$_SESSION['username']
OR
$this->session->userdata('username')
OR
$this->session->username

Finally, make sure the cookies are actually being deleted by inspecting your requests in network tab. Codeigniter deletes cookies by setting a negative expiration time of around a day, see if this is the case in your version of Codeigniter. For best results, just set the cookie again with large negative expiration time, and instead of checking if cookie is set, check if cookie is !empty.

1. To unset single element from session array:

   $this->session->unset_userdata('some_name');

2. You can pass an array of keys to unset multiple values:

   $array_items = array('username' => '', 'email' => ''); $this->session->unset_userdata($array_items);

public function check_admin_login()
    {
        $admin_email_address=$this->input->post('admin_email_address',true);
        $admin_password=$this->input->post('admin_password',true);
        $this->load->model('admin_model','a_model');
       $result= $this->a_model->check_admin_login_info($admin_email_address,$admin_password);
//       echo '<pre>';
//       print_r($result);
//       exit();
       $sdata=array();

       if($result)
       {
           $sdata['full_name']=$result->admin_full_name;
           $sdata['admin_id']=$result->admin_id;
           $this->session->set_userdata($sdata);
           //$sdata[]
           redirect('super_admin');
       }
       else{
           $sdata['message']='Your User Id / Password Invalide !';
           $this->session->set_userdata($sdata);
           $this->load->view('admin/admin_login');
       }
    }


for login and for logout


  public function logout()
    {
        $this->session->unset_userdata('full_name');
        $this->session->unset_userdata('admin_id');
        $sdata=array();
        $sdata['message']='You are Successfully Logout !';
        $this->session->set_userdata($sdata);
        redirect('admin');



    }

For delete cookie

delete_cookie('name', $domain, $path); 

For delete/destroy sesstion

$this->session->sess_destroy();

To destroy a particular session

$this->session->unset_userdata('name');

For multiple items

$items = array('item-name1' => '', 'item-name2' => '');

$this->session->unset_userdata($items);