获取屏幕宽高

function getBrowserInterfaceSize() {
    var pageWidth = window.innerWidth;
    var pageHeight = window.innerHeight;

    if (typeof pageWidth != "number") {
        pageWidth = document.documentElement.clientWidth || document.body.clientWidth;
        pageHeight = document.documentElement.clientHeight || document.body.clientHeight;
    }

    return {
        pageWidth: pageWidth,
        pageHeight: pageHeight
    }
}