class StringOP
    {
        ///
        /// 获取中英文混排字符串的实际长度(字节数)
        ///
        /// 要获取长度的字符串
        /// 字符串的实际长度值（字节数）
        public int getStringLength(string str)
        {
            if (str.Equals(string.Empty))
                return 0;
            int strlen = 0;
            ASCIIEncoding strData = new ASCIIEncoding();
            //将字符串转换为ASCII编码的字节数字
            byte[] strBytes = strData.GetBytes(str);
            for (int i = 0; i 0)
                    {
                        j++;
                    }
                }
            }
            return j;
        }

byte[] sarr = System.Text.Encoding.Default.GetBytes(s);  
 int len = sarr.Length;