export default class myUtils {
     // 计算元素滚动条宽度
     static getScrollWidth(elemOrSelect) {
        if (!elemOrSelect) return;
        if (elemOrSelect.constructor === String) elemOrSelect = document.querySelector(elemOrSelect);
        //参数为html或body时获取浏览器默认滚动条宽度
        if (/BODY|HTML/.test(elemOrSelect.nodeName)) {
            elemOrSelect.style.padding = 0; 
            elemOrSelect.style.margin = 0;
            return window.innerWidth - elemOrSelect.clientWidth;
        }
        //兼容
        var style = elemOrSelect.currentStyle ? elemOrSelect.currentStyle : getComputedStyle(elemOrSelect).style;
        //获取某个元素滚动条宽度
        var width =
            elemOrSelect.offsetWidth
            - Math.ceil(parseFloat(style.borderLeftWidth))
            - Math.ceil(parseFloat(style.borderRightWidth))
            - elemOrSelect.clientWidth;
        return width;
    }
}