获取Internet服务器的时间
using System; using System.Net; using System.Net.Sockets; namespace SNTPTime { // 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 } /// /// Initialize - Sets up data structure and prepares for connection. /// /// Connect - Connects to the time server and populates the data structure. /// /// 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 SNTPTimeClient { // 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: 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: case 6: case 7: 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: case _Stratum.PrimaryReference: val += Convert.ToChar(NTPData[offReferenceID + 0]); val += Convert.ToChar(NTPData[offReferenceID + 1]); val += Convert.ToChar(NTPData[offReferenceID + 2]); val += Convert.ToChar(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 //// { //// IPAddress RefAddr = new IPAddress(Address); //// IPHostEntry Host = DNS.GetHostByAddr(RefAddr); //// 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 //// long offset = TimeZone.CurrentTimeZone.GetUTCOffset(DateTime.Now); //// TimeSpan offspan = TimeSpan.FromTicks(offset); //// val = (time + offspan).ToString(); //// break; //// default: //// val = "N/A"; //// } break; } return val; } } // Reference Timestamp public DateTime ReferenceTimestamp { get { DateTime time = ComputeDate(GetMilliSeconds(offReferenceTimestamp)); // Take care of the time zone long offset = Convert.ToInt64(TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.Now)); TimeSpan offspan = TimeSpan.FromTicks(offset); 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 long offset = TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.Now).Ticks; TimeSpan offspan = TimeSpan.FromTicks(offset); return time + offspan; } } // Transmit Timestamp public DateTime TransmitTimestamp { get { DateTime time = ComputeDate(GetMilliSeconds(offTransmitTimestamp)); // Take care of the time zone long offset = TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.Now).Ticks; TimeSpan offspan = TimeSpan.FromTicks(offset); 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; } // Connect to the time server public void Connect() { try { IPAddress hostadd = IPAddress.Parse(TimeServer); IPEndPoint EPhost = new IPEndPoint(hostadd, Convert.ToInt32(TimePort)); UdpClient TimeSocket = new UdpClient(); TimeSocket.Connect(EPhost); 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); } } // 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 += " Version number: " + VersionNumber.ToString() + " "; 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 += " Stratum: "; 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 += " Local time: " + TransmitTimestamp.ToString(); str += " Precision: " + Precision.ToString() + " ms"; str += " Poll Interval: " + PollInterval.ToString() + " s"; str += " Reference ID: " + ReferenceID.ToString(); str += " Root Dispersion: " + RootDispersion.ToString() + " ms"; str += " Round Trip Delay: " + RoundTripDelay.ToString() + " ms"; str += " Local Clock Offset: " + LocalClockOffset.ToString() + " ms"; str += " "; return str; } // The URL of the time server we're connecting to private string TimeServer; private string TimePort; public SNTPTimeClient(string host, string port) { TimeServer = host; TimePort = port; } } } 调用： SNTPTime.SNTPTimeClient client = new SNTPTime.SNTPTimeClient("210.72.145.44", "123"); client.Connect(); string strTest = client.ToString();
获取当前系统时间
－－DateTime 数字型
System.DateTime currentTime=new System.DateTime();
取当前年月日时分秒 currentTime=System.DateTime.Now;
取当前年 int 年=currentTime.Year;
取当前月 int 月=currentTime.Month;
取当前日 int 日=currentTime.Day;
取当前时 int 时=currentTime.Hour;
取当前分 int 分=currentTime.Minute;
取当前秒 int 秒=currentTime.Second;
取当前毫秒 int 毫秒=currentTime.Millisecond; （变量可用中文）
取中文日期显示——年月日时分 string strY=currentTime.ToString("f"); //不显示秒
取中文日期显示_年月 string strYM=currentTime.ToString("y");
取中文日期显示_月日 string strMD=currentTime.ToString("m");
取当前年月日，格式为：2003-9-23 string strYMD=currentTime.ToString("d");
取当前时分，格式为：14：24 string strT=currentTime.ToString("t");
DateTime.Now.ToString();//获取当前系统时间 完整的日期和时间
DateTime.Now.ToLongDateString();//只显示日期 xxxx年xx月xx日 ，一个是长日期
DateTime.Now.ToShortDateString();//只显示日期 xxxx-xx-xx 一个是短日期
//今天 DateTime.Now.Date.ToShortDateString();
//昨天 的 DateTime.Now.AddDays(-1).ToShortDateString();
//明天 的 DateTime.Now.AddDays(1).ToShortDateString();
//本周(注意这里的每一周是从周日始至周六止）
DateTime.Now.AddDays(Convert.ToDouble((0 - Convert.ToInt16(DateTime.Now.DayOfWeek)))).ToShortDateString();
DateTime.Now.AddDays(Convert.ToDouble((6 - Convert.ToInt16(DateTime.Now.DayOfWeek)))).ToShortDateString();
//上周，上周就是本周再减去7天
DateTime.Now.AddDays(Convert.ToDouble((0 - Convert.ToInt16(DateTime.Now.DayOfWeek))) - 7).ToShortDateString();
DateTime.Now.AddDays(Convert.ToDouble((6 - Convert.ToInt16(DateTime.Now.DayOfWeek))) - 7).ToShortDateString();
//下周 本周再加上7天
DateTime.Now.AddDays(Convert.ToDouble((0 - Convert.ToInt16(DateTime.Now.DayOfWeek))) + 7).ToShortDateString();
DateTime.Now.AddDays(Convert.ToDouble((6 - Convert.ToInt16(DateTime.Now.DayOfWeek))) + 7).ToShortDateString();
//本月 本月的第一天是1号，最后一天就是下个月一号再减一天。
DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + "1"; //第一天
DateTime.Parse(DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + "1").AddMonths(1).AddDays(-1).ToShortDateString();//最后一天
另一种方法：
DateTime now = DateTime.Now;
DateTime d1 = new DateTime(now.Year, now.Month, 1); //本月第一天
DateTime d2 = d1.AddMonths(1).AddDays(-1); //本月最后一天
PS：
DateTime.Now.DayOfWeek.ToString();//英文星期显示，Wednesday
（int）DateTime.Now.DayOfWeek 数字，若是周三，结果对应为3
DateTime.Now.ToString("dddd", new System.Globalization.CultureInfo("zh-cn")); //中文星期显示
DateTime.Now.ToString("dddd");//中文星期显示
DateTime.Now.ToString("dddd,MMMM,dd ,yyyy", new System.Globalization.DateTimeFormatInfo())；//显示日期格式Friday,July, 01,2009
DateTime.Now.ToString("dddd,dd MMMM,yyyy") //输出 星期三,30 一月,2008
出处：http://msdn.microsoft.com/zh-cn/vstudio/bb762911(VS.95).aspx，如何：从特定日期中提取星期几
datetime类型在tostring()format的格式设置
参数format格式详细用法
格式字符 关联属性/说明
d ShortDatePattern
D LongDatePattern
f 完整日期和时间（长日期和短时间）
F FullDateTimePattern（长日期和长时间）
g 常规（短日期和短时间）
G 常规（短日期和长时间）
m、M MonthDayPattern
r、R RFC1123Pattern
s 使用当地时间的 SortableDateTimePattern（基于 ISO 8601）
t ShortTimePattern
T LongTimePattern
u UniversalSortableDateTimePattern 用于显示通用时间的格式
U 使用通用时间的完整日期和时间（长日期和长时间）
y、Y YearMonthPattern
下表列出了可被合并以构造自定义模式的模式。这些模式是区分大小写的
d 月中的某一天。一位数的日期没有前导零。
dd 月中的某一天。一位数的日期有一个前导零。
ddd 周中某天的缩写名称，在 AbbreviatedDayNames 中定义。
dddd 周中某天的完整名称，在 DayNames 中定义。
M 月份数字。一位数的月份没有前导零。
MM 月份数字。一位数的月份有一个前导零。
MMM 月份的缩写名称，在 AbbreviatedMonthNames 中定义。
MMMM 月份的完整名称，在 MonthNames 中定义。
y 不包含纪元的年份。如果不包含纪元的年份小于 10，则显示不具有前导零的年份。
yy 不包含纪元的年份。如果不包含纪元的年份小于 10，则显示具有前导零的年份。
yyyy 包括纪元的四位数的年份。
gg 时期或纪元。如果要设置格式的日期不具有关联的时期或纪元字符串，则忽略该模式。
h 12 小时制的小时。一位数的小时数没有前导零。
hh 12 小时制的小时。一位数的小时数有前导零。
H 24 小时制的小时。一位数的小时数没有前导零。
HH 24 小时制的小时。一位数的小时数有前导零。
获取北京时间多种方法
#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 = @"hrss+=s+d{1,2}"; string patMn = @"mins+=s+d{1,2}"; string patSc = @"secs+=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 /// <summary> /// 获取标准北京时间1 /// </summary> /// <returns></returns> public static DateTime GetStandardTime() { //<?xml version="1.0" encoding="GB2312" ?> //- <ntsc> //- <time> // <year>2011</year> // <month>7</month> // <day>10</day> // <Weekday /> // <hour>19</hour> // <minite>45</minite> // <second>37</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("2011-1-1"); } catch (Exception) { return DateTime.Parse("2011-1-1"); } finally { if (wrp != null) wrp.Close(); if (wrt != null) wrt.Abort(); } return dt; } /// <summary> /// 获取标准北京时间2 /// </summary> /// <returns></returns> public static DateTime GetBeijingTime() { //t0 = new Date().getTime(); //nyear = 2011; //nmonth = 7; //nday = 5; //nwday = 2; //nhrs = 17; //nmin = 12; //nsec = 12; DateTime dt; WebRequest wrt = null; WebResponse wrp = null; try { wrt = WebRequest.Create("http://www.beijing-time.org/time.asp"); wrp = wrt.GetResponse(); string html = string.Empty; using (Stream stream = wrp.GetResponseStream()) { using (StreamReader sr = new StreamReader(stream, Encoding.UTF8)) { html = sr.ReadToEnd(); } } string[] tempArray = html.Split(';'); for (int i = 0; i < tempArray.Length; i++) { tempArray[i] = tempArray[i].Replace(" ", ""); } string year = tempArray[1].Substring(tempArray[1].IndexOf("nyear=") + 6); string month = tempArray[2].Substring(tempArray[2].IndexOf("nmonth=") + 7); string day = tempArray[3].Substring(tempArray[3].IndexOf("nday=") + 5); string hour = tempArray[5].Substring(tempArray[5].IndexOf("nhrs=") + 5); string minite = tempArray[6].Substring(tempArray[6].IndexOf("nmin=") + 5); string second = tempArray[7].Substring(tempArray[7].IndexOf("nsec=") + 5); dt = DateTime.Parse(year + "-" + month + "-" + day + " " + hour + ":" + minite + ":" + second); } catch (WebException) { return DateTime.Parse("2011-1-1"); } catch (Exception) { return DateTime.Parse("2011-1-1"); } finally { if (wrp != null) wrp.Close(); if (wrt != null) wrt.Abort(); } return dt; } /// <summary> /// 获取标准北京时间 /// </summary> /// <returns></returns> public static DateTime DataStandardTime() { DateTime dt; //返回国际标准时间 //只使用的时间服务器的IP地址，未使用域名 try { string[,] 时间服务器 = new string[14, 2]; int[] 搜索顺序 = new int[] { 3, 2, 4, 8, 9, 6, 11, 5, 10, 0, 1, 7, 12 }; 时间服务器[0, 0] = "time-a.nist.gov"; 时间服务器[0, 1] = "129.6.15.28"; 时间服务器[1, 0] = "time-b.nist.gov"; 时间服务器[1, 1] = "129.6.15.29"; 时间服务器[2, 0] = "time-a.timefreq.bldrdoc.gov"; 时间服务器[2, 1] = "132.163.4.101"; 时间服务器[3, 0] = "time-b.timefreq.bldrdoc.gov"; 时间服务器[3, 1] = "132.163.4.102"; 时间服务器[4, 0] = "time-c.timefreq.bldrdoc.gov"; 时间服务器[4, 1] = "132.163.4.103"; 时间服务器[5, 0] = "utcnist.colorado.edu"; 时间服务器[5, 1] = "128.138.140.44"; 时间服务器[6, 0] = "time.nist.gov"; 时间服务器[6, 1] = "192.43.244.18"; 时间服务器[7, 0] = "time-nw.nist.gov"; 时间服务器[7, 1] = "131.107.1.10"; 时间服务器[8, 0] = "nist1.symmetricom.com"; 时间服务器[8, 1] = "69.25.96.13"; 时间服务器[9, 0] = "nist1-dc.glassey.com"; 时间服务器[9, 1] = "216.200.93.8"; 时间服务器[10, 0] = "nist1-ny.glassey.com"; 时间服务器[10, 1] = "208.184.49.9"; 时间服务器[11, 0] = "nist1-sj.glassey.com"; 时间服务器[11, 1] = "207.126.98.204"; 时间服务器[12, 0] = "nist1.aol-ca.truetime.com"; 时间服务器[12, 1] = "207.200.81.113"; 时间服务器[13, 0] = "nist1.aol-va.truetime.com"; 时间服务器[13, 1] = "64.236.96.53"; int portNum = 13; string hostName; byte[] bytes = new byte[1024]; int bytesRead = 0; System.Net.Sockets.TcpClient client = new System.Net.Sockets.TcpClient(); for (int i = 0; i < 13; i++) { hostName = 时间服务器[搜索顺序[i], 1]; try { client.Connect(hostName, portNum); System.Net.Sockets.NetworkStream ns = client.GetStream(); bytesRead = ns.Read(bytes, 0, bytes.Length); client.Close(); break; } catch (System.Exception) { } } char[] sp = new char[1]; sp[0] = ' '; dt = new DateTime(); string str1; str1 = System.Text.Encoding.ASCII.GetString(bytes, 0, bytesRead); string[] s; s = str1.Split(sp); if (s.Length >= 2) { dt = System.DateTime.Parse(s[1] + " " + s[2]);//得到标准时间 dt = dt.AddHours(8);//得到北京时间*/ } else { dt = DateTime.Parse("2011-1-1"); } } catch (Exception) { dt = DateTime.Parse("2011-1-1"); } return dt; } 调用示例： DateTime dt = Common.GetBeijingTime();// Common.GetStandardTime(); if (dt.ToString() == "2011-1-1 0:00:00") { MessageBox.Show("网络异常，不能启动本程序！"); Application.Exit(); return; }
时间比较
use "DateTime.Compare" static method DateTime.Compare( dt1, dt2 ) > 0 : dt1 > dt2 DateTime.Compare( dt1, dt2 ) == 0 : dt1 == dt2 DateTime.Compare( dt1, dt2 ) < 0 : dt1 < dt2 /// <summary> /// 计算两个日期的时间间隔 /// </summary> /// <param name="DateTime1">第一个日期和时间</param> /// <param name="DateTime2">第二个日期和时间</param> /// <returns></returns> private string DateDiff(DateTime DateTime1, DateTime DateTime2) { string dateDiff = null; TimeSpan ts1 = new TimeSpan(DateTime1.Ticks); TimeSpan ts2 = new TimeSpan(DateTime2.Ticks); TimeSpan ts = ts1.Subtract(ts2).Duration(); dateDiff = ts.Days.ToString()+"天" + ts.Hours.ToString()+"小时" + ts.Minutes.ToString()+"分钟" + ts.Seconds.ToString()+"秒"; return dateDiff; }
说明：
1.DateTime值类型代表了一个从公元0001年1月1日0点0分0秒到公元9999年12月31日23点59分59秒之间的具体日期时刻。因此，你可以用DateTime值类型来描述任何在想象范围之内的时间。一个DateTime值代表了一个具体的时刻
2.TimeSpan值包含了许多属性与方法，用于访问或处理一个TimeSpan值
下面的列表涵盖了其中的一部分：
Add：与另一个TimeSpan值相加。
Days:返回用天数计算的TimeSpan值。
Duration:获取TimeSpan的绝对值。
Hours:返回用小时计算的TimeSpan值
Milliseconds:返回用毫秒计算的TimeSpan值。
Minutes:返回用分钟计算的TimeSpan值。
Negate:返回当前实例的相反数。
Seconds:返回用秒计算的TimeSpan值。
Subtract:从中减去另一个TimeSpan值。
Ticks:返回TimeSpan值的tick数。
TotalDays:返回TimeSpan值表示的天数。
TotalHours:返回TimeSpan值表示的小时数。
TotalMilliseconds:返回TimeSpan值表示的毫秒数。
TotalMinutes:返回TimeSpan值表示的分钟数。
TotalSeconds:返回TimeSpan值表示的秒数。
时间差的操作
c#计算时间差重点：
c#计算时间差函数TimeSpan的应用
TimeSpan值包含了许多属性与方法，用于访问或处理一个TimeSpan值
下面的列表涵盖了其中的一部分：
Add：与另一个TimeSpan值相加。
Days:返回用天数计算的TimeSpan值。
Duration:获取TimeSpan的绝对值。
Hours:返回用小时计算的TimeSpan值
Milliseconds:返回用毫秒计算的TimeSpan值。
Minutes:返回用分钟计算的TimeSpan值。
Negate:返回当前实例的相反数。
Seconds:返回用秒计算的TimeSpan值。
Subtract:从中减去另一个TimeSpan值。
Ticks:返回TimeSpan值的tick数。
TotalDays:返回TimeSpan值表示的天数。
TotalHours:返回TimeSpan值表示的小时数。
TotalMilliseconds:返回TimeSpan值表示的毫秒数。
TotalMinutes:返回TimeSpan值表示的分钟数。
TotalSeconds:返回TimeSpan值表示的秒数。
c#计算时间差实现方法：
DateTime DateTime1, DateTime2 = DateTime.Now ;//现在时间 DateTime1 =Convert.ToDateTime("2009-04-24 20:00:00"); //设置要求的减的时间 string dateDiff = null; TimeSpan ts1 = new TimeSpan(DateTime1.Ticks); TimeSpan ts2 = new TimeSpan(DateTime2.Ticks); TimeSpan ts = ts1.Subtract(ts2).Duration(); //显示时间 dateDiff = ts.Days.ToString() + "天" + ts.Hours.ToString() + "小时" + ts.Minutes.ToString() + "分钟" + ts.Seconds.ToString() + "秒";
获取网络时间
using System; using System.Data; using System.Text; using System.Runtime.InteropServices; using System.Net; using System.Net.Sockets; namespace getInterTime { struct SystemTime { public ushort wYear; public ushort wMonth; public ushort wDayOfWeek; public ushort wDay; public ushort wHour; public ushort wMinute; public ushort wSecond; public ushort wMilliseconds; /// <summary> /// 从System.DateTime转换。 /// </summary> /// <param name="time">System.DateTime类型的时间。</param> public void FromDateTime(DateTime time) { wYear = (ushort)time.Year; wMonth = (ushort)time.Month; wDayOfWeek = (ushort)time.DayOfWeek; wDay = (ushort)time.Day; wHour = (ushort)time.Hour; wMinute = (ushort)time.Minute; wSecond = (ushort)time.Second; wMilliseconds = (ushort)time.Millisecond; } /// <summary> /// 转换为System.DateTime类型。 /// </summary> /// <returns></returns> public DateTime ToDateTime() { return new DateTime(wYear, wMonth, wDay, wHour, wMinute, wSecond, wMilliseconds); } /// <summary> /// 静态方法。转换为System.DateTime类型。 /// </summary> /// <param name="time">SYSTEMTIME类型的时间。</param> /// <returns></returns> public static DateTime ToDateTime(SystemTime time) { return time.ToDateTime(); } } class Win32API { [DllImport("Kernel32.dll")] public static extern bool SetLocalTime(ref SystemTime Time); [DllImport("Kernel32.dll")] public static extern void GetLocalTime(ref SystemTime Time); } class Program { static void Main(string[] args) { getInternetTime(); Console.ReadLine(); } public static void getInternetTime() { // 记录开始的时间 DateTime startDT = DateTime.Now; //建立IPAddress对象与端口，创建IPEndPoint节点: int port = 13; string[] whost = { "time-nw.nist.gov", "5time.nist.gov", "time-a.nist.gov", "time-b.nist.gov", "tick.mit.edu", "time.windows.com", "clock.sgi.com" }; IPHostEntry iphostinfo; IPAddress ip; IPEndPoint ipe; Socket c = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//创建Socket c.ReceiveTimeout = 10 * 1000;//设置超时时间 string sEX = "";// 接受错误信息 // 遍历时间服务器列表 foreach (string strHost in whost) { try { iphostinfo = Dns.GetHostEntry(strHost); ip = iphostinfo.AddressList[0]; ipe = new IPEndPoint(ip, port); c.Connect(ipe);//连接到服务器 if (c.Connected) break;// 如果连接到服务器就跳出 } catch (Exception ex) { } } //SOCKET同步接受数据 byte[] RecvBuffer = new byte[1024]; int nBytes, nTotalBytes = 0; StringBuilder sb = new StringBuilder(); System.Text.Encoding myE = Encoding.UTF8; try { while ((nBytes = c.Receive(RecvBuffer, 0, 1024, SocketFlags.None)) > 0) { nTotalBytes += nBytes; sb.Append(myE.GetString(RecvBuffer, 0, nBytes)); } } catch (System.Exception ex) { } //关闭连接 c.Close(); string[] o = sb.ToString().Split(' '); // 打断字符串 TimeSpan k = new TimeSpan(); k = (TimeSpan)(DateTime.Now - startDT);// 得到开始到现在所消耗的时间 DateTime SetDT = Convert.ToDateTime(o[1] + " " + o[2]).Subtract(-k);// 减去中途消耗的时间 //处置北京时间 +8时 SetDT = SetDT.AddHours(8); //转换System.DateTime到SystemTime SystemTime st = new SystemTime(); st.FromDateTime(SetDT); Console.WriteLine(st.ToDateTime().ToString()); //这里可以输出获得的互联网时间 //Win32API.SetLocalTime(ref st);//如果选择不输出，也可以使用API设置为系统的时间，API函数申明见上面的Win32API类 } } }