獲取頁面滾動條的寬度

    function getScrollBarWidth() {
        var e = document.createElement("p"),
            styless = {
                width: "100px",
                height: "100px",
                overflowY: "scroll"
            },
            i;

        for (i in styles) {
            e.style[i] = styless[i];
        }
        document.body.appendChild(e);
        var scrollBarWidth = e.offsetWidth - e.clientWidth;
        e.remove();
        return scrollBarWidth;
    }

調用即可

           function getScrollBarWidth() {
            var e = document.createElement("p"),
                styless = {
                    width: "100px",
                    height: "100px",
                    overflowY: "scroll"
                },
                i;

            for (i in styles) {
                e.style[i] = styless[i];
            }
            document.body.appendChild(e);
            var scrollBarWidth = e.offsetWidth - e.clientWidth;
            e.remove();
            return scrollBarWidth;
        }
    

註明此方法有0.2px的偏差，可以根據情況適當的加減此偏差