移动端头部

    <script>
        // 立即生成兼容VIEWPORT
        (function () {
            var phoneWidth = parseInt(window.screen.width);
            var phoneScale = phoneWidth / 640;
            var ua = navigator.userAgent;
            if (/Android (\d+\.\d+)/.test(ua)) {
                var version = parseFloat(RegExp.$1);
                if (version > 2.3) {
                    // andriod 2.3以上
                    document.write('<meta name="viewport" content="width=640, minimum-scale = ' + phoneScale + ', maximum-scale = ' + phoneScale + ', target-densitydpi=device-dpi">');
                } else {
                    // andriod 2.3
                    document.write('<meta name="viewport" content="width=640, target-densitydpi=device-dpi">');
                }
                // IOS及其他系统
            } else {
                document.write('<meta name="viewport" content="width=640, user-scalable=no">');
            }
        })()
    </script>

转载于:https://my.oschina.net/zhubaoxin/blog/1581537