同步时间C＃
我有一个C＃.net程序，它部署在不同的机器上。 我希望此程序的所有实例都使用与Windows时间服务器同步的“DateTime”变量。
最好的方法是什么？
更新开始
我能想到的另一种方法是公开一个服务，该服务将在其运行的机器中返回UTC时间，并在其他机器上运行的其他应用程序中使用相同的时间。
更新结束
如果您了解支持简单网络时间协议（SNTP）的授权时间服务器，您可以使用@ http://dotnet-snippets.com/snippet/simple-network-time-ntp-protocol-中记录的代码来阅读时间。 客户机/ 571
将代码放在下面以供参考。
/* * AC# SNTP Client * * Copyright (C)2001-2003 Valer BOCAN * All Rights Reserved * * You may download the latest version from http://www.dataman.ro * Last modified: September 20, 2003 * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, and/or sell copies of the Software, and to permit persons * to whom the Software is furnished to do so, provided that the above * copyright notice(s) and this permission notice appear in all copies of * the Software and that both the above copyright notice(s) and this * permission notice appear in supporting documentation. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT * OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR * HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * Disclaimer * ---------- * Although reasonable care has been taken to ensure the correctness of this * implementation, this code should never be used in any application without * proper verification and testing. I disclaim all liability and responsibility * to any person or entity with respect to any loss or damage caused, or alleged * to be caused, directly or indirectly, by the use of this SNTPClient class. * * Comments, bugs and suggestions are welcome. * * Update history: * September 20, 2003 * - Renamed the class from NTPClient to SNTPClient. * - Fixed the RoundTripDelay and LocalClockOffset properties. * Thanks go to DNH . * - Fixed the PollInterval property. * Thanks go to Jim Hollenhorst . * - Changed the ReceptionTimestamp variable to DestinationTimestamp to follow the standard * more closely. * - Precision property is now shown is seconds rather than milliseconds in the * ToString method. * * May 28, 2002 * - Fixed a bug in the Precision property and the SetTime function. * Thanks go to Jim Hollenhorst . * * March 14, 2001 * - First public release. */ namespace InternetTime { using System; using System.Net; using System.Net.Sockets; using System.Runtime.InteropServices; // Leap indicator field values public enum _LeapIndicator { NoWarning, // 0 - No warning LastMinute61, // 1 - Last minute has 61 seconds LastMinute59, // 2 - Last minute has 59 seconds Alarm // 3 - Alarm condition (clock not synchronized) } //Mode field values public enum _Mode { SymmetricActive, // 1 - Symmetric active SymmetricPassive, // 2 - Symmetric pasive Client, // 3 - Client Server, // 4 - Server Broadcast, // 5 - Broadcast Unknown // 0, 6, 7 - Reserved } // Stratum field values public enum _Stratum { Unspecified, // 0 - unspecified or unavailable PrimaryReference, // 1 - primary reference (eg radio-clock) SecondaryReference, // 2-15 - secondary reference (via NTP or SNTP) Reserved // 16-255 - reserved } /// /// SNTPClient is a C# class designed to connect to time servers on the Internet and /// fetch the current date and time. Optionally, it may update the time of the local system. /// The implementation of the protocol is based on the RFC 2030. /// /// Public class members: /// /// LeapIndicator - Warns of an impending leap second to be inserted/deleted in the last /// minute of the current day. (See the _LeapIndicator enum) /// /// VersionNumber - Version number of the protocol (3 or 4). /// /// Mode - Returns mode. (See the _Mode enum) /// /// Stratum - Stratum of the clock. (See the _Stratum enum) /// /// PollInterval - Maximum interval between successive messages /// /// Precision - Precision of the clock /// /// RootDelay - Round trip time to the primary reference source. /// /// RootDispersion - Nominal error relative to the primary reference source. /// /// ReferenceID - Reference identifier (either a 4 character string or an IP address). /// /// ReferenceTimestamp - The time at which the clock was last set or corrected. /// /// OriginateTimestamp - The time at which the request departed the client for the server. /// /// ReceiveTimestamp - The time at which the request arrived at the server. /// /// Transmit Timestamp - The time at which the reply departed the server for client. /// /// RoundTripDelay - The time between the departure of request and arrival of reply. /// /// LocalClockOffset - The offset of the local clock relative to the primary reference /// source. /// /// Initialize - Sets up data structure and prepares for connection. /// /// Connect - Connects to the time server and populates the data structure. /// It can also update the system time. /// /// IsResponseValid - Returns true if received data is valid and if comes from /// a NTP-compliant time server. /// /// ToString - Returns a string representation of the object. /// /// ----------------------------------------------------------------------------- /// Structure of the standard NTP header (as described in RFC 2030) /// 1 2 3 /// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// |LI | VN |Mode | Stratum | Poll | Precision | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// | Root Delay | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// | Root Dispersion | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// | Reference Identifier | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// | | /// | Reference Timestamp (64) | /// | | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// | | /// | Originate Timestamp (64) | /// | | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// | | /// | Receive Timestamp (64) | /// | | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// | | /// | Transmit Timestamp (64) | /// | | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// | Key Identifier (optional) (32) | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// | | /// | | /// | Message Digest (optional) (128) | /// | | /// | | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// /// ----------------------------------------------------------------------------- /// /// SNTP Timestamp Format (as described in RFC 2030) /// 1 2 3 /// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// | Seconds | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// | Seconds Fraction (0-padded) | /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /// /// public class SNTPClient { // SNTP Data Structure Length private const byte SNTPDataLength = 48; // SNTP Data Structure (as described in RFC 2030) byte []SNTPData = new byte[SNTPDataLength]; // Offset constants for timestamps in the data structure private const byte offReferenceID = 12; private const byte offReferenceTimestamp = 16; private const byte offOriginateTimestamp = 24; private const byte offReceiveTimestamp = 32; private const byte offTransmitTimestamp = 40; // Leap Indicator public _LeapIndicator LeapIndicator { get { // Isolate the two most significant bits byte val = (byte)(SNTPData[0] >> 6); switch(val) { case 0: return _LeapIndicator.NoWarning; case 1: return _LeapIndicator.LastMinute61; case 2: return _LeapIndicator.LastMinute59; case 3: goto default; default: return _LeapIndicator.Alarm; } } } // Version Number public byte VersionNumber { get { // Isolate bits 3 - 5 byte val = (byte)((SNTPData[0] & 0x38) >> 3); return val; } } // Mode public _Mode Mode { get { // Isolate bits 0 - 3 byte val = (byte)(SNTPData[0] & 0x7); switch(val) { case 0: goto default; case 6: goto default; case 7: goto default; default: return _Mode.Unknown; case 1: return _Mode.SymmetricActive; case 2: return _Mode.SymmetricPassive; case 3: return _Mode.Client; case 4: return _Mode.Server; case 5: return _Mode.Broadcast; } } } // Stratum public _Stratum Stratum { get { byte val = (byte)SNTPData[1]; if(val == 0) return _Stratum.Unspecified; else if(val == 1) return _Stratum.PrimaryReference; else if(val <= 15) return _Stratum.SecondaryReference; else return _Stratum.Reserved; } } // Poll Interval (in seconds) public uint PollInterval { get { // Thanks to Jim Hollenhorst return (uint)(Math.Pow(2, (sbyte)SNTPData[2])); } } // Precision (in seconds) public double Precision { get { // Thanks to Jim Hollenhorst return (Math.Pow(2, (sbyte)SNTPData[3])); } } // Root Delay (in milliseconds) public double RootDelay { get { int temp = 0; temp = 256 * (256 * (256 * SNTPData[4] + SNTPData[5]) + SNTPData[6]) + SNTPData[7]; return 1000 * (((double)temp) / 0x10000); } } // Root Dispersion (in milliseconds) public double RootDispersion { get { int temp = 0; temp = 256 * (256 * (256 * SNTPData[8] + SNTPData[9]) + SNTPData[10]) + SNTPData[11]; return 1000 * (((double)temp) / 0x10000); } } // Reference Identifier public string ReferenceID { get { string val = ""; switch(Stratum) { case _Stratum.Unspecified: goto case _Stratum.PrimaryReference; case _Stratum.PrimaryReference: val += (char)SNTPData[offReferenceID + 0]; val += (char)SNTPData[offReferenceID + 1]; val += (char)SNTPData[offReferenceID + 2]; val += (char)SNTPData[offReferenceID + 3]; break; case _Stratum.SecondaryReference: switch(VersionNumber) { case 3: // Version 3, Reference ID is an IPv4 address string Address = SNTPData[offReferenceID + 0].ToString() + "." + SNTPData[offReferenceID + 1].ToString() + "." + SNTPData[offReferenceID + 2].ToString() + "." + SNTPData[offReferenceID + 3].ToString(); try { IPHostEntry Host = Dns.GetHostEntry(Address); val = Host.HostName + " (" + Address + ")"; } catch(Exception) { val = "N/A"; } break; case 4: // Version 4, Reference ID is the timestamp of last update DateTime time = ComputeDate(GetMilliSeconds(offReferenceID)); // Take care of the time zone TimeSpan offspan = TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.Now); val = (time + offspan).ToString(); break; default: val = "N/A"; break; } break; } return val; } } // Reference Timestamp public DateTime ReferenceTimestamp { get { DateTime time = ComputeDate(GetMilliSeconds(offReferenceTimestamp)); // Take care of the time zone TimeSpan offspan = TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.Now); return time + offspan; } } // Originate Timestamp (T1) public DateTime OriginateTimestamp { get { return ComputeDate(GetMilliSeconds(offOriginateTimestamp)); } } // Receive Timestamp (T2) public DateTime ReceiveTimestamp { get { DateTime time = ComputeDate(GetMilliSeconds(offReceiveTimestamp)); // Take care of the time zone TimeSpan offspan = TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.Now); return time + offspan; } } // Transmit Timestamp (T3) public DateTime TransmitTimestamp { get { DateTime time = ComputeDate(GetMilliSeconds(offTransmitTimestamp)); // Take care of the time zone TimeSpan offspan = TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.Now); return time + offspan; } set { SetDate(offTransmitTimestamp, value); } } // Destination Timestamp (T4) public DateTime DestinationTimestamp; // Round trip delay (in milliseconds) public int RoundTripDelay { get { // Thanks to DNH TimeSpan span = (DestinationTimestamp - OriginateTimestamp) - (ReceiveTimestamp - TransmitTimestamp); return (int)span.TotalMilliseconds; } } // Local clock offset (in milliseconds) public int LocalClockOffset { get { // Thanks to DNH TimeSpan span = (ReceiveTimestamp - OriginateTimestamp) + (TransmitTimestamp - DestinationTimestamp); return (int)(span.TotalMilliseconds / 2); } } // Compute date, given the number of milliseconds since January 1, 1900 private DateTime ComputeDate(ulong milliseconds) { TimeSpan span = TimeSpan.FromMilliseconds((double)milliseconds); DateTime time = new DateTime(1900, 1, 1); time += span; return time; } // Compute the number of milliseconds, given the offset of a 8-byte array private ulong GetMilliSeconds(byte offset) { ulong intpart = 0, fractpart = 0; for(int i = 0; i <= 3; i++) { intpart = 256 * intpart + SNTPData[offset + i]; } for(int i = 4; i<=7; i++) { fractpart = 256 * fractpart + SNTPData[offset + i]; } ulong milliseconds = intpart * 1000 + (fractpart * 1000) / 0x100000000L; return milliseconds; } // Compute the 8-byte array, given the date private void SetDate(byte offset, DateTime date) { ulong intpart = 0, fractpart = 0; DateTime StartOfCentury = new DateTime(1900, 1, 1, 0, 0, 0); // January 1, 1900 12:00 AM ulong milliseconds = (ulong)(date - StartOfCentury).TotalMilliseconds; intpart = milliseconds / 1000; fractpart=((milliseconds % 1000) * 0x100000000L) / 1000; ulong temp = intpart; for(int i = 3; i >= 0; i--) { SNTPData[offset + i] = (byte) (temp % 256); temp = temp / 256; } temp = fractpart; for(int i = 7; i >=4; i--) { SNTPData[offset + i] = (byte) (temp % 256); temp = temp / 256; } } // Initialize the NTPClient data private void Initialize() { // Set version number to 4 and Mode to 3 (client) SNTPData[0] = 0x1B; // Initialize all other fields with 0 for(int i = 1; i < 48; i++) { SNTPData[i] = 0; } // Initialize the transmit timestamp TransmitTimestamp = DateTime.Now; } public SNTPClient(string host) { TimeServer = host; } // Connect to the time server and update system time public void Connect(bool UpdateSystemTime) { try { // Resolve server address IPHostEntry hostadd = Dns.GetHostEntry(TimeServer); IPEndPoint EPhost = new IPEndPoint(hostadd.AddressList[0], 123); //Connect the time server UdpClient TimeSocket = new UdpClient(); TimeSocket.Connect(EPhost); // Initialize data structure Initialize(); TimeSocket.Send(SNTPData, SNTPData.Length); SNTPData = TimeSocket.Receive(ref EPhost); if(!IsResponseValid()) { throw new Exception("Invalid response from " + TimeServer); } DestinationTimestamp = DateTime.Now; } catch(SocketException e) { throw new Exception(e.Message); } // Update system time if(UpdateSystemTime) { SetTime(); } } // Check if the response from server is valid public bool IsResponseValid() { if(SNTPData.Length < SNTPDataLength || Mode != _Mode.Server) { return false; } else { return true; } } // Converts the object to string public override string ToString() { string str; str = "Leap Indicator: "; switch(LeapIndicator) { case _LeapIndicator.NoWarning: str += "No warning"; break; case _LeapIndicator.LastMinute61: str += "Last minute has 61 seconds"; break; case _LeapIndicator.LastMinute59: str += "Last minute has 59 seconds"; break; case _LeapIndicator.Alarm: str += "Alarm Condition (clock not synchronized)"; break; } str += "\r\nVersion number: " + VersionNumber.ToString() + "\r\n"; str += "Mode: "; switch(Mode) { case _Mode.Unknown: str += "Unknown"; break; case _Mode.SymmetricActive: str += "Symmetric Active"; break; case _Mode.SymmetricPassive: str += "Symmetric Pasive"; break; case _Mode.Client: str += "Client"; break; case _Mode.Server: str += "Server"; break; case _Mode.Broadcast: str += "Broadcast"; break; } str += "\r\nStratum: "; switch(Stratum) { case _Stratum.Unspecified: case _Stratum.Reserved: str += "Unspecified"; break; case _Stratum.PrimaryReference: str += "Primary Reference"; break; case _Stratum.SecondaryReference: str += "Secondary Reference"; break; } str += "\r\nLocal time: " + TransmitTimestamp.ToString(); str += "\r\nPrecision: " + Precision.ToString() + " s"; str += "\r\nPoll Interval: " + PollInterval.ToString() + " s"; str += "\r\nReference ID: " + ReferenceID.ToString(); str += "\r\nRoot Delay: " + RootDelay.ToString() + " ms"; str += "\r\nRoot Dispersion: " + RootDispersion.ToString() + " ms"; str += "\r\nRound Trip Delay: " + RoundTripDelay.ToString() + " ms"; str += "\r\nLocal Clock Offset: " + LocalClockOffset.ToString() + " ms"; str += "\r\n"; return str; } // SYSTEMTIME structure used by SetSystemTime [StructLayoutAttribute(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; } [DllImport("kernel32.dll")] static extern bool SetLocalTime(ref SYSTEMTIME time); // Set system time according to transmit timestamp private void SetTime() { SYSTEMTIME st; // Thanks to Jim Hollenhorst DateTime trts = DateTime.Now.AddMilliseconds(LocalClockOffset); st.year = (short)trts.Year; st.month = (short)trts.Month; st.dayOfWeek = (short)trts.DayOfWeek; st.day = (short)trts.Day; st.hour = (short)trts.Hour; st.minute = (short)trts.Minute; st.second = (short)trts.Second; st.milliseconds = (short)trts.Millisecond; SetLocalTime(ref st); } // The URL of the time server we're connecting to private string TimeServer; } } 使用时间服务器或时间服务器 。 这将允许您肯定地知道服务器的所有呼叫者都具有高度准确性。
最好在依赖服务器同步服务不足的情况下使用它。 例如Azure就是一个想到的案例……