当我将此Doctype放入文档document.body.scrollTop返回零.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
这是为什么？
解决方法:
使用该Doctype时,会将当前的所有浏览器都放在所谓的Almost Standards mode中,如果没有它,您将处于Quirks模式.
正如您在this page上所读到的,
[m]ost browsers provide
window.pageXOffset/pageYOffset. These are completely reliable. Once again, Internet Explorer is the odd one out, as it does not provide these properties. Internet Explorer and some other browsers will providedocument.body.scrollLeft/Top. In strict mode, IE 6 and a few other browsers, providedocument.documentElement.scrollLeft/Top.
那里提供的脚本计算所需的值：
function getScrollXY() {
var scrOfX = 0, scrOfY = 0;
if( typeof( window.pageYOffset ) == 'number' ) {
//Netscape compliant
scrOfY = window.pageYOffset;
scrOfX = window.pageXOffset;
} else if( document.body && ( document.body.scrollLeft || document.body.scrollTop ) ) {
//DOM compliant
scrOfY = document.body.scrollTop;
scrOfX = document.body.scrollLeft;
} else if( document.documentElement && ( document.documentElement.scrollLeft || document.documentElement.scrollTop ) ) {
//IE6 standards compliant mode
scrOfY = document.documentElement.scrollTop;
scrOfX = document.documentElement.scrollLeft;
}
return [ scrOfX, scrOfY ];
}
另一个有趣的文章出现在QuirksMode,A tale of two viewports上.