WordPress手机移动设备判断：如何识别访问者是否使用移动设备

现在手机移动设备越来越普及，也越来越智能，使用手机浏览网页已经比较流行了，所以，作为WordPress主题开发者，你必须好好考虑如何应对手机移动用户了。
这是一段php通用的判断移动浏览器的函数，原理比较简单，就是判断浏览器返回的user_agent，条件包括手机系统、品牌和窗口大小。
以WordPress为例，在主题的 functions.php内加上如下代码，目前已包含常见移动浏览器的useragent，基本上可以涵盖可能会用手机上网的用户群了。

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;}

然后在主题任意模板如顶部加上如下判断：

<?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 ;?>

还需要注意的一点：不管是单独的WordPress主题还是自适应主题，都需要在头部将添加下面meta，否者可能导致手机显示字体过小等问题。

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