Codeigniter表单网址无法正常工作

I am using codeigniter and smarty template in one of my project.

So in controller I have assign variable like this.

$data['form'] = array("type" => "form_open_multipart" , "action" => base_url()."files/edit/".$file_id);

but on the browser when I check the form action url it displayed "�http://...."

� char is replaced with first char of url.

this happen only with the form_open_multipart() method, with form_open() method it is working fine.

How can I remove that sign from url?

there is some hidden character in your base_url variable in application/config/config.php : you can verify that or simply change it to a dynamic one as follow :

$config['base_url'] = ((isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == "on") ? "https" : "http");
$config['base_url'] .= "://" . $_SERVER['HTTP_HOST'];
$config['base_url'] .= str_replace(basename($_SERVER['SCRIPT_NAME']), "", $_SERVER['SCRIPT_NAME']);