C#获取北京时间与设置系统时间

获取北京时间

 public static DateTime GetBeijingTime()
 {
     DateTime dt;

     // 返回国际标准时间
     // 只使用 timeServers 的 IP 地址，未使用域名
     try
     {
         string[,] timeServers = new string[, ];
         int[] searchOrder = { , , , , , , , , , , , ,  };
         timeServers[, ] = "time-a.nist.gov";
         timeServers[, ] = "129.6.15.28";
         timeServers[, ] = "time-b.nist.gov";
         timeServers[, ] = "129.6.15.29";
         timeServers[, ] = "time-a.timefreq.bldrdoc.gov";
         timeServers[, ] = "132.163.4.101";
         timeServers[, ] = "time-b.timefreq.bldrdoc.gov";
         timeServers[, ] = "132.163.4.102";
         timeServers[, ] = "time-c.timefreq.bldrdoc.gov";
         timeServers[, ] = "132.163.4.103";
         timeServers[, ] = "utcnist.colorado.edu";
         timeServers[, ] = "128.138.140.44";
         timeServers[, ] = "time.nist.gov";
         timeServers[, ] = "192.43.244.18";
         timeServers[, ] = "time-nw.nist.gov";
         timeServers[, ] = "131.107.1.10";
         timeServers[, ] = "nist1.symmetricom.com";
         timeServers[, ] = "69.25.96.13";
         timeServers[, ] = "nist1-dc.glassey.com";
         timeServers[, ] = "216.200.93.8";
         timeServers[, ] = "nist1-ny.glassey.com";
         timeServers[, ] = "208.184.49.9";
         timeServers[, ] = "nist1-sj.glassey.com";
         timeServers[, ] = "207.126.98.204";
         timeServers[, ] = "nist1.aol-ca.truetime.com";
         timeServers[, ] = "207.200.81.113";
         timeServers[, ] = "nist1.aol-va.truetime.com";
         timeServers[, ] = "64.236.96.53";
         int portNum = ;
         byte[] bytes = new byte[];
         int bytesRead = ;
         System.Net.Sockets.TcpClient client = new System.Net.Sockets.TcpClient();
         for (int i = ; i < ; i++)
         {
             string hostName = timeServers[searchOrder[i], ];
             try
             {
                 client.Connect(hostName, portNum);
                 System.Net.Sockets.NetworkStream ns = client.GetStream();
                 bytesRead = ns.Read(bytes, , bytes.Length);
                 client.Close();
                 break;
             }
             catch (Exception)
             {
                 // ignored
             }
         }
         char[] sp = new char[];
         sp[] = ' ';
         dt = new DateTime();
         string str1 = System.Text.Encoding.ASCII.GetString(bytes, , bytesRead);

         string[] s = str1.Split(sp);
         if (s.Length >= )
         {
             dt = DateTime.Parse(s[] + " " + s[]); // 得到标准时间
             dt = dt.AddHours();                    // 得到北京时间
         }
         else
         {
             dt = DateTime.Parse("2016-1-1");
         }
     }
     catch (Exception)
     {
         dt = DateTime.Parse("2016-1-1");
     }
     return dt;
 }            

设置本地系统时间

 [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;
 }

 public static bool SetDate(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;

     bool rt = SetLocalTime(ref st);
     return rt;
 }