JS 中获得根目录

/***
 * 获得根目录
 * @returns
 */
function getRootPath() {
    var strFullPath = window.document.location.href;
    var strPath = window.document.location.pathname;
    var pos = strFullPath.indexOf(strPath);
    var prePath = strFullPath.substring(0, pos);
    var postPath = strPath.substring(0, strPath.substr(1).indexOf('/') + 1);
    return (prePath + postPath);
}