时间的处理--与网络时间同步

         #region  获取网络时间
         ///   <summary>
         ///  获取中国国家授时中心网络服务器时间发布的当前时间
         ///   </summary>
         ///   <returns></returns>
         public   static  DateTime GetChineseDateTime()
        {
            DateTime res  =  DateTime.MinValue;
             try
            {
                 string  url  =   " http://www.time.ac.cn/stime.asp " ;
                HttpHelper helper  =   new  HttpHelper();
                helper.Encoding  =  Encoding.Default;
                 string  html  =  helper.GetHtml(url);
                 string  patDt  =   @" \d{4}年\d{1,2}月\d{1,2}日 " ;
                 string  patHr  =   @" hrs\s+=\s+\d{1,2} " ;
                 string  patMn  =   @" min\s+=\s+\d{1,2} " ;
                 string  patSc  =   @" sec\s+=\s+\d{1,2} " ;
                Regex regDt  =   new  Regex(patDt);
                Regex regHr  =   new  Regex(patHr);
                Regex regMn  =   new  Regex(patMn);
                Regex regSc  =   new  Regex(patSc);

                res  =  DateTime.Parse(regDt.Match(html).Value);
                 int  hr  =  GetInt(regHr.Match(html).Value,  false );
                 int  mn  =  GetInt(regMn.Match(html).Value,  false );
                 int  sc  =  GetInt(regSc.Match(html).Value,  false );
                res  =  res.AddHours(hr).AddMinutes(mn).AddSeconds(sc);
            }
             catch  { }
             return  res;
        }

         ///   <summary>
         ///  从指定的字符串中获取整数
         ///   </summary>
         ///   <param name="origin"> 原始的字符串 </param>
         ///   <param name="fullMatch"> 是否完全匹配，若为false，则返回字符串中的第一个整数数字 </param>
         ///   <returns> 整数数字 </returns>
         private   static   int  GetInt( string  origin,  bool  fullMatch)
        {
             if  ( string .IsNullOrEmpty(origin))
            {
                 return   0 ;
            }
            origin  =  origin.Trim();
             if  ( ! fullMatch)
            {
                 string  pat  =   @" -?\d+ " ;
                Regex reg  =   new  Regex(pat);
                origin  =  reg.Match(origin.Trim()).Value;
            }
             int  res  =   0 ;
             int .TryParse(origin,  out  res);
             return  res;
        }
         #endregion

         #region  P/Invoke 设置本地时间

        [DllImport( " kernel32.dll " )]
         private   static   extern   bool  SetLocalTime( ref  SYSTEMTIME time);

        [StructLayout(LayoutKind.Sequential)]
         private   struct  SYSTEMTIME
        {
             public   short  year;
             public   short  month;
             public   short  dayOfWeek;
             public   short  day;
             public   short  hour;
             public   short  minute;
             public   short  second;
             public   short  milliseconds;
        }

         ///   <summary>
         ///  设置本地计算机时间
         ///   </summary>
         ///   <param name="dt"> DateTime对象 </param>
         public   static   void  SetLocalTime(DateTime dt)
        {
            SYSTEMTIME st;

            st.year  =  ( short )dt.Year;
            st.month  =  ( short )dt.Month;
            st.dayOfWeek  =  ( short )dt.DayOfWeek;
            st.day  =  ( short )dt.Day;
            st.hour  =  ( short )dt.Hour;
            st.minute  =  ( short )dt.Minute;
            st.second  =  ( short )dt.Second;
            st.milliseconds  =  ( short )dt.Millisecond;

            SetLocalTime( ref  st);
        }

         #endregion