JS——scroll封装

DTD未声明：document.body.scrollTop

DTD已声明：document.documentElement.scrollTop

火狐谷歌IE9：window.pageYOffset

compatMode：可以判断是否声明DTD，CSS1Compat是，BackCompat否

复杂版本：

<script>
    window.onscroll = function () {
        console.log(scroll().left + "  " + scroll().top);
    }

    function scroll() {
        if (window.pageYOffset) {
            return {
                "top": window.pageYOffset,
                "left": window.pageXOffset
            };
        } else if (document.compatMode == "CSS1Compat") {
            return {
                "top": document.documentElement.scrollTop,
                "left": document.documentElement.scrollLeft
            };
        } else {
            return {
                "top": document.body.scrollTop,
                "left": document.body.scrollLeft
            };
        }
    }
</script>

简单版本：

<script>
    window.onscroll = function () {
        console.log(scroll().left + "  " + scroll().top);
    }

    function scroll() {
        return {
            "top": window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop,
            "left": window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft
        };
    }
</script>