截取字符串显示指定长度,超过部分用省略

function getInterceptedStr(sSource, iLen) {
    if (sSource.replace(/[^\x00-\xff]/g, "xx").length <= iLen) {
        return sSource;
    }
    var str = "";
    var l = 0;
    var schar;
    for (var i = 0; schar = sSource.charAt(i); i++) {
        str += schar;
        l += (schar.match(/[^\x00-\xff]/) != null ? 2: 1);
        if (l >= iLen) {
            str += "....";
            break;
        }
    }
    return str;
}