实例介绍
【实例截图】
【核心代码】
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 | /* * NTPClient * Copyright (C)2001 Valer BOCAN <vbocan@dataman.ro> * Last modified: June 29, 2001 * All Rights Reserved * * This code is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY, without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * * To fully understand the concepts used herein, I strongly * recommend that you read the RFC 2030. * * NOTE: This example is intended to be compiled with Visual Studio .NET Beta 2 */ namespace TimeSync { 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 (e.g. radio-clock) SecondaryReference, // 2-15 - secondary reference (via NTP or SNTP) Reserved // 16-255 - reserved } /// <summary> /// NTPClient is a C# class designed to connect to time servers on the Internet. /// 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 set 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) | /// | | /// | | /// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - /// /// ----------------------------------------------------------------------------- /// /// NTP 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) | /// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - /// /// </summary> public class NTPClient { // NTP Data Structure Length private const byte NTPDataLength = 48; // NTP Data Structure (as described in RFC 2030) byte []NTPData = new byte [NTPDataLength]; // 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 )(NTPData[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 )((NTPData[0] & 0x38) >> 3); return val; } } // Mode public _Mode Mode { get { // Isolate bits 0 - 3 byte val = ( byte )(NTPData[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 )NTPData[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 public uint PollInterval { get { return ( uint )Math.Round(Math.Pow(2, NTPData[2])); } } // Precision (in milliseconds) public double Precision { get { return (1000 * Math.Pow(2, NTPData[3])); } } // Root Delay (in milliseconds) public double RootDelay { get { int temp = 0; temp = 256 * (256 * (256 * NTPData[4] NTPData[5]) NTPData[6]) NTPData[7]; return 1000 * ((( double )temp) / 0x10000); } } // Root Dispersion (in milliseconds) public double RootDispersion { get { int temp = 0; temp = 256 * (256 * (256 * NTPData[8] NTPData[9]) NTPData[10]) NTPData[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 )NTPData[offReferenceID 0]; val = ( char )NTPData[offReferenceID 1]; val = ( char )NTPData[offReferenceID 2]; val = ( char )NTPData[offReferenceID 3]; break ; case _Stratum.SecondaryReference: switch (VersionNumber) { case 3: // Version 3, Reference ID is an IPv4 address string Address = NTPData[offReferenceID 0].ToString() "." NTPData[offReferenceID 1].ToString() "." NTPData[offReferenceID 2].ToString() "." NTPData[offReferenceID 3].ToString(); try { IPHostEntry Host = Dns.GetHostByAddress(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 public DateTime OriginateTimestamp { get { return ComputeDate(GetMilliSeconds(offOriginateTimestamp)); } } // Receive Timestamp 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 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); } } // Reception Timestamp public DateTime ReceptionTimestamp; // Round trip delay (in milliseconds) public int RoundTripDelay { get { TimeSpan span = (ReceiveTimestamp - OriginateTimestamp) (ReceptionTimestamp - TransmitTimestamp); return ( int )span.TotalMilliseconds; } } // Local clock offset (in milliseconds) public int LocalClockOffset { get { TimeSpan span = (ReceiveTimestamp - OriginateTimestamp) - (ReceptionTimestamp - TransmitTimestamp); 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 NTPData[offset i]; } for ( int i = 4; i<=7; i ) { fractpart = 256 * fractpart NTPData[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--) { NTPData[offset i] = ( byte ) (temp % 256); temp = temp / 256; } temp = fractpart; for ( int i = 7; i >=4; i--) { NTPData[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) NTPData[0] = 0x1B; // Initialize all other fields with 0 for ( int i = 1; i < 48; i ) { NTPData[i] = 0; } // Initialize the transmit timestamp TransmitTimestamp = DateTime.Now; } public NTPClient( 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.Resolve(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(NTPData, NTPData.Length); NTPData = TimeSocket.Receive( ref EPhost); if (!IsResponseValid()) { throw new Exception( "Invalid response from " TimeServer); } ReceptionTimestamp = 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 (NTPData.Length < NTPDataLength || 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() " ms" ; str = "\r\nPoll Interval: " PollInterval.ToString() " s" ; str = "\r\nReference ID: " ReferenceID.ToString(); 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; DateTime trts = TransmitTimestamp; 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; } } |
标签: 时间
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