C#实现从网络同步标准北京时间的方法

#region
/// <summary>
/// 获取标准北京时间
/// /// </summary>
/// /// <returns></returns>
///
public static DateTime GetStandardTime()   
{
/// //<?xml version="1.0" encoding="GB2312" ?>
//- <ntsc>
//- <time>
// <year>2013</year>
// <month>8</month>
// <day>29</day> 
// <Weekday /> 
// <hour>16</hour>
// <minite>29</minite>
// <second>12</second> 
// <Millisecond />
// </time> 
// </ntsc> 
DateTime dt;
WebRequest wrt = null;
WebResponse wrp = null;
try
{
wrt = WebRequest.Create("http://www.time.ac.cn/timeflash.asp?user=flash"); 
wrt.Credentials = CredentialCache.DefaultCredentials;
  wrp = wrt.GetResponse();
  StreamReader sr = new StreamReader(wrp.GetResponseStream(),Encoding.UTF8);
  string html = sr.ReadToEnd();
  sr.Close();
  wrp.Close();
  int yearIndex = html.IndexOf("<year>") + 6;
  int monthIndex = html.IndexOf("<month>") + 7;
  int dayIndex = html.IndexOf("<day>") + 5;
  int hourIndex = html.IndexOf("<hour>") + 6;
  int miniteIndex = html.IndexOf("<minite>") + 8;
  int secondIndex = html.IndexOf("<second>") + 8;
  string year = html.Substring(yearIndex, html.IndexOf("</year>") - yearIndex);
  string month = html.Substring(monthIndex, html.IndexOf("</month>") - monthIndex);
  string day = html.Substring(dayIndex, html.IndexOf("</day>") - dayIndex);
  string hour = html.Substring(hourIndex, html.IndexOf("</hour>") - hourIndex);
  string minite = html.Substring(miniteIndex, html.IndexOf("</minite>") - miniteIndex);
  string second = html.Substring(secondIndex, html.IndexOf("</second>") - secondIndex);
  dt = DateTime.Parse(year + "-" + month + "-" + day + " " + hour + ":" + minite + ":" + second);
}
catch (WebException)
{
  return DateTime.Parse("2013-1-1");
}
catch (Exception)
{
  return DateTime.Parse("2013-1-1");
}
finally
{
  if (wrp != null)
 wrp.Close();
  if (wrt != null)
 wrt.Abort();
}
   return dt;
 }
#endregion