cookie不在codeigniter中显示

I set a cookie with Codeigniter and it is Ok because I can see it in browser settings, but it doesn't shows when I am coding.
set cookie:

$login_text = "$username is loged in!";
            $this->load->library('encrypt');
            $cookie_value = $this->encrypt->encode($login_text, ENCRYPTION_KEY);

            $data_cookie = array(
                'name'   => 'userRemember',
                'value'  => strval($cookie_value),
                'expire' => '1209600'
            );

read cookie:

print_r($this->input->cookie());  

what is the problem?and how can I solve it?

You need to use setcookie()

Setcookie("name", "value", "expire time");

Replace the strings with your values
Edit:

 Setcookie($data_cookie['name'], $data_cookie['value'], $data_cookie['expire']);

To read the cookie

Echo $_COOKIE($data_cookie['name']);