function strlen(str) {

        var len = 0;

        for (var i = 0; i < str.length; i++) {

            var c = str.charCodeAt(i);

            //单字节加1

            if ((c >= 0x0001 && c <= 0x007e) || (0xff60 <= c && c <= 0xff9f)) {

                len++;

            }

            else {

                len += 2;

            }

        }

        return len;

    }