jQuery 获取屏幕高度、宽度

alert($(window).height()); //浏览器当前窗口可视区域高度 

alert($(document).height()); //浏览器当前窗口文档的高度 

alert($(document.body).height());//浏览器当前窗口文档body的高度 

alert($(document.body).outerHeight(true));//浏览器当前窗口文档body的总高度 包括border padding margin 

alert($(window).width()); //浏览器当前窗口可视区域宽度 

alert($(document).width());//浏览器当前窗口文档对象宽度 

alert($(document.body).width());//浏览器当前窗口文档body的高度 

alert($(document.body).outerWidth(true));//浏览器当前窗口文档body的总宽度 包括border padding margin 

// 获取页面的高度、宽度

function getPageSize() {

    var xScroll, yScroll;

    if (window.innerHeight && window.scrollMaxY) {

        xScroll = window.innerWidth + window.scrollMaxX;

        yScroll = window.innerHeight + window.scrollMaxY;

    } else {

        if (document.body.scrollHeight > document.body.offsetHeight) { // all but Explorer Mac    

            xScroll = document.body.scrollWidth;

            yScroll = document.body.scrollHeight;

        } else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari    

            xScroll = document.body.offsetWidth;

            yScroll = document.body.offsetHeight;

        }

    }

    var windowWidth, windowHeight;

    if (self.innerHeight) { // all except Explorer    

        if (document.documentElement.clientWidth) {

            windowWidth = document.documentElement.clientWidth;

        } else {

            windowWidth = self.innerWidth;

        }

        windowHeight = self.innerHeight;

    } else {

        if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode    

            windowWidth = document.documentElement.clientWidth;

            windowHeight = document.documentElement.clientHeight;

        } else {

            if (document.body) { // other Explorers    

                windowWidth = document.body.clientWidth;

                windowHeight = document.body.clientHeight;

            }

        }

    }       

    // for small pages with total height less then height of the viewport    

    if (yScroll < windowHeight) {

        pageHeight = windowHeight;

    } else {

        pageHeight = yScroll;

    }    

    // for small pages with total width less then width of the viewport    

    if (xScroll < windowWidth) {

        pageWidth = xScroll;

    } else {

        pageWidth = windowWidth;

    }

    arrayPageSize = new Array(pageWidth, pageHeight, windowWidth, windowHeight);

    return arrayPageSize;

}

// 滚动条

document.body.scrollTop;

$(document).scrollTop();