中国語と英語の文字の長さの検査(ASCII符号化を回転する)

/// <summary>

        ///  

        /// </summary>

        /// <param name="str"></param>

        /// <returns></returns>

        public int StrLength(string str)

        {

            if (str.Equals(string.Empty))

                return 0;

            int strlen = 0;

            ASCIIEncoding strData = new ASCIIEncoding();

            // ASCII 

            byte[] strBytes = strData.GetBytes(str);

            for (int i = 0; i <= strBytes.Length - 1; i++)

            {

                if (strBytes[i] == 63)  // ASCII 63, "?" 

                    strlen++;

                strlen++;

            }

            return strlen;

        }