mysqli_connect_error乱码解决思路

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='
数据库连接失败
';
	$str.="
可能的原因有：数据库防火墙未关闭、数据库服务未启用
";
	$str.="
返回的错误信息是 %s
";
	$str.="
";
	printf ($str,mysqli_connect_error());
	exit();
};
?>

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

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