设置窗口宽度

setViewPort.js

setViewPort(640);

/**
 * 设置窗口宽度
 * @param width
 */
function setViewPort(width) {
    var scale     = window.screen.width / width,
        isAndroid = /Android (\d+\.\d+)/.test(navigator.userAgent);

    isAndroid
        ? document.write('<meta name="viewport" content="width=' + width + ', minimum-scale = ' + scale + ', maximum-scale = ' + scale +', target-densitydpi=device-dpi')
        : document.write('<meta name="viewport" content="width=' + width + ', user-scalable=no">');
}