Undefined property: App\Controllers\Signup::$input

Can't pass form data from view to SignUp controller. 

home.php
<?php

helper('form');

echo form_open('Signup');


echo form_input('user_email','',['placeholder'=>'Email Address'],'email');
echo form_input('user_password','',['placeholder'=>'Password'],'password');

echo form_submit('mysubmit','SignUp');
?>



Signup.php

<?php

namespace App\Controllers;

use CodeIgniter\Controller;


class Signup extends Controller
{


    public function index()
    {

if($this->input->post('mysubmit')!=NULL)
{

$mailids=$this->input->post('user_email');

      echo $mailids;

  } 

}

}

?>