function is_mobile() {

    $user_agent = $_SERVER['HTTP_USER_AGENT'];

    $mobile_browser = Array(

        "mqqbrowser", //手机QQ浏览器

        "opera mobi", //手机opera

        "juc","iuc",//uc浏览器

        "fennec","ios","applewebKit/420","applewebkit/525","applewebkit/532","ipad","iphone","ipaq","ipod",

        "iemobile", "windows ce",//windows phone

        "240x320","480x640","acer","android","anywhereyougo.com","asus","audio","blackberry","blazer","coolpad" ,"dopod", "etouch", "hitachi","htc","huawei", "jbrowser", "lenovo","lg","lg-","lge-","lge", "mobi","moto","nokia","phone","samsung","sony","symbian","tablet","tianyu","wap","xda","xde","zte"

    );

    $is_mobile = false;

    foreach ($mobile_browser as $device) {

        if (stristr($user_agent, $device)) {

            $is_mobile = true;

            break;

        }

    }

    return $is_mobile;}

<?php if (is_mobile() ): ?>

    //如何如何..(这里可以添加一个mobile.css,如<link rel="stylesheet" type="text/css" media="all" href="http://www.jqueryba.com/"<?php echo get_template_directory_uri(); ?>/mobile.css" />)

<?php endif ;?>

<meta name="viewport" content="width=device-width"/>