获取远程服务器的准确时间

Question

在 C# 中，如何查询远程服务器的当前时间？

与

类似的功能

net time \\servername

但返回包含秒数的日期戳。

谢谢

Answer 1

您可以使用NetRemoteTOD 函数。

来自http://bytes.com/groups/net-c/246234-netremotetod-usage的例子：

// The pointer.
IntPtr pintBuffer = IntPtr.Zero;

// Get the time of day.
int pintError = NetRemoteTOD(@"\\sony_laptop", ref pintBuffer);

// Get the structure.
TIME_OF_DAY_INFO pobjInfo = (TIME_OF_DAY_INFO)
Marshal.PtrToStructure(pintBuffer, typeof(TIME_OF_DAY_INFO));

// Free the buffer.
NetApiBufferFree(pintBuffer);

Answer 2

您可以尝试在端口 13 上获取白天：

System.Net.Sockets.TcpClient t = new System.Net.Sockets.TcpClient ("yourmachineHOST", 13);
System.IO.StreamReader rd = new System.IO.StreamReader (t.GetStream ()); 
Console.WriteLine (rd.ReadToEnd ());
rd.Close();
t.Close();

Answer 3

下面是更完整的实现。

用法：DateTime? now = RemoteTOD.GetNow(@"\\ServerName");

using System;
using System.ComponentModel;
using System.Runtime.InteropServices;

//https://docs.microsoft.com/en-us/windows/desktop/api/lmremutl/nf-lmremutl-netremotetod
public static class RemoteTOD {

    // Important: CharSet must be Unicode otherwise error 2184 is returned
    [DllImport("netapi32.dll", SetLastError=true, CharSet=CharSet.Unicode)]
    private static extern int NetRemoteTOD(String UncServerName, ref IntPtr BufferPtr);

    [DllImport("netapi32.dll")]
    private static extern void NetApiBufferFree(IntPtr bufptr);

    public static DateTime? GetNow(String serverName, bool throwException = false) {
        IntPtr ptrBuffer = IntPtr.Zero;
        int result = NetRemoteTOD(serverName, ref ptrBuffer);
        if (result != 0) {
            if (throwException)
                throw new Win32Exception(Marshal.GetLastWin32Error());
            return null;
        }

        TIME_OF_DAY_INFO tod = (TIME_OF_DAY_INFO) Marshal.PtrToStructure(ptrBuffer, typeof(TIME_OF_DAY_INFO));
        NetApiBufferFree(ptrBuffer); // must be freed using NetApiBufferFree according to the documentation

        //DateTime d0 = new DateTime(1970,1,1);
        //d0 = d0.AddSeconds(tod.elapsedt);
        DateTime nowUtc = new DateTime(tod.year, tod.month, tod.day, tod.hour, tod.minute, tod.second, 10 * tod.hunds);
        DateTime now = nowUtc.ToLocalTime();
        return now;
    }
}

[StructLayout(LayoutKind.Sequential)]
public struct TIME_OF_DAY_INFO {

    ///<summary>The number of seconds since 00:00:00, January 1, 1970, GMT.</summary>
    public int elapsedt;

    ///<summary>The number of milliseconds from an arbitrary starting point (system reset). Typically, this member is read twice,
    ///once when the process begins and again at the end. To determine the elapsed time between the process's start and finish,
    ///you can subtract the first value from the second.</summary>
    public int msecs;

    ///<summary>The current hour. Valid values are 0 through 23.</summary>
    public int hour;

    ///<summary>The current minute. Valid values are 0 through 59.</summary>
    public int minute;

    ///<summary>The current second. Valid values are 0 through 59.</summary>
    public int second;

    ///<summary>The current hundredth second (0.01 second). Valid values are 0 through 99.</summary>
    public int hunds;

    ///<summary>The time zone of the server. This value is calculated, in minutes, from Greenwich Mean Time (GMT). For time zones
    ///west of Greenwich, the value is positive; for time zones east of Greenwich, the value is negative. A value of –1 indicates
    ///that the time zone is undefined.</summary>
    public int timezone;

    ///<summary>The time interval for each tick of the clock. Each integral integer represents one ten-thousandth second (0.0001 second).</summary>
    public int tinterval;

    ///<summary>The day of the month. Valid values are 1 through 31.</summary>
    public int day;

    ///<summary>The month of the year. Valid values are 1 through 12.</summary>
    public int month;

    ///<summary>The year.</summary>
    public int year;

    ///<summary>The day of the week. Valid values are 0 through 6, where 0 is Sunday, 1 is Monday, and so on.</summary>
    public int weekday;
}

Answer 4

Windows 时间服务实现了 NTP。这是C# implementation of an NTP client。使用它的 Windows GUI 可以在Simple Network Time Protocol Client 找到。这是 Valer Bocan 的作品。

Answer 5

使用 Reed Copsey (& David Laing) 答案中的 C# NTP client，您可以使用以下方式从域控制器/NTP 服务器获取“现在”时间戳（以毫秒为单位）：

InternetTime.SNTPClient sntp = new InternetTime.SNTPClient("ntp1.ja.net");
sntp.Connect(false); // true to update local client clock
DateTime dt = sntp.DestinationTimestamp.AddMilliseconds(sntp.LocalClockOffset);
string timeStampNow = dt.ToString("dd/MM/yyyy HH:mm:ss.fff");

Answer 6

Simple Network Time Protocol Client

Answer 7

如果您可以通过 UNC 路径访问远程系统的文件系统（例如 \\remotehost\foo\bar；例如使用 Windows 资源管理器），您可以检索远程日期时间，即使它是不是 Windows 系统，有以下解决方法。创建一个虚拟文件，读取它的写入时间并将其丢弃。它也适用于本地主机。

public DateTime filesystemDateTime(string path)
{
    //create temp file
    string tempFilePath = Path.Combine(path, "lampo.tmp");
    using (File.Create(tempFilePath)) { }
    //read creation time and use it as current source filesystem datetime
    DateTime dt = new FileInfo(tempFilePath).LastWriteTime;
    //delete temp file
    File.Delete(tempFilePath);

    return dt;
}

Answer 8

class RemoteSystemTime 
    {
        static void Main(string[] args)
        {
            try
            {
                string machineName = "vista-pc";

                System.Diagnostics.Process proc = new System.Diagnostics.Process();
                proc.StartInfo.UseShellExecute = false;
                proc.StartInfo.RedirectStandardOutput = true;
                proc.StartInfo.FileName = "net";
                proc.StartInfo.Arguments = @"time \\" + machineName;
                proc.Start();
                proc.WaitForExit();

                List<string> results = new List<string>();
                while (!proc.StandardOutput.EndOfStream)
                {
                    string currentline = proc.StandardOutput.ReadLine();
                    if (!string.IsNullOrEmpty(currentline))
                    {
                        results.Add(currentline);
                    }
                }

                string currentTime = string.Empty;
                if (results.Count > 0 && results[0].ToLower().StartsWith(@"current time at \\" +                                               machineName.ToLower() + " is "))
                {
                    currentTime = results[0].Substring((@"current time at \\" + machineName.ToLower() + " is                             ").Length);

                    Console.WriteLine(DateTime.Parse(currentTime));
                    Console.ReadLine();
                }

            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                Console.ReadLine();
            }
        }