php - 如何在 Codeigniter 中检查 session 是否已设置？

Question

我知道如何在核心 PHP 中创建 session ，我也了解如何在 codeigniter 中执行此操作，但我无法理解如何检查是否设置了 session ？我试图通过 View 对此进行检查，但它总是给我提示 Please Login。

请告诉我如何检查 session 是否已设置

Controller

if ($user_type=='Student')
{
  if ($LoginData=   $this->loginmodel->studentLogin($username,$password))
  {
    foreach($LoginData as $UserId)
    {
      $currentId= $UserId->StudentId;
    }
    //[[session]]

    $data['students_data']=         $this->loginmodel->student_profile($currentId);

    $this->session->userdata('$data');

    $this->load->view('students',$data);
  }
  else
  { 
  //$data['message']= array('Invalid Username or Password');
    $this->load->view('Login');
    echo "Invalid Username or Password";
  }
}
elseif ($user_type=="Faculty")
{
  if($data['faculty_data']=$this->loginmodel->faculty_admin($username, $password))
  {
    $this->session->userdata('$data');

    $this->load->view('faculty');
  }
  else
  {
    $this->load->view('Login');
    echo "Invalid Username or Password";
  }
}

查看

<?php 

if (!$this->session->userdata('$data'))
{
    echo "Please Login";
}
else
{

}

?>

<!DOCTYPE

Answer 1

创建 session :

$newdata = array(
               'username'  => 'johndoe',
               'email'     => 'johndoe@some-site.com',
               'logged_in' => TRUE
           );

$this->session->set_userdata($newdata);

或

  $this->session->set_userdata('some_name', 'some_value');

但在此之前，请确保您已包含 session 库。

$this->load->library('session');

获取 session 数据:

if($this->session->userdata('whatever_session_name_is')){
     // do something when exist
}else{
    // do something when doesn't exist
}