c# Unicode 转换 ASCII

  /// <summary>
        /// Unicode 转换 ASCII
        /// </summary>
        /// <param name="theText">解码内容</param>
        /// <returns></returns>
        public static string unHTMLEncode(string theText)
        {
            try
            {
                string output = string.Empty;
                if (theText.Contains("&#"))
                {
                    return System.Text.RegularExpressions.Regex.Replace(
                    theText,
                    @"&#(?<Value>[a-zA-Z0-9]{5});",
                    m =>
                    {
                        return ((char)int.Parse(m.Groups["Value"].Value)).ToString();
                    });
                }
                string[] stringArray = theText.Split(' ');

                if (stringArray.Length == 1)
                    return theText;

                for (int i = 0; i < stringArray.Length - 1; i++)
                {
                    int n;
                    if (int.TryParse(stringArray[i], out n))
                        output += (char)int.Parse(stringArray[i]);
                    else
                        output += stringArray[i];
                }

                return output;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }