mysqli_connect_error 乱码解决思路

mysqli_connect_error 乱码
代码如下

header("Content-Type: text/html; charset=utf-8");
$db_host='127.0.0.1';
$db_host='192.168.0.22';
$db_user='root';
$db_pwd='';
$db_name='iq1';
@$mysqli=new mysqli($db_host,$db_user,$db_pwd,$db_name);

if (mysqli_connect_errno()){
	$str='

header("Content-Type: text/html; charset=utf-8");

printf ($str, iconv('gbk', 'utf-8', mysqli_connect_error()));