如何使用C#修改本地Windows系统时间

来源：jb51　　时间：2021/1/25 11:27:24　　对本文有异议

C#提升管理员权限修改本地Windows系统时间

在桌面应用程序开发过程中，需要对C盘下进行文件操作或者系统参数进行设置，例如在没有外网的情况下局域网内部自己的机制进行时间同步校准，这是没有管理员权限便无法进行设置。

1. 首先需要获得校准时间，两种方式：

通过可上网的电脑进行外部获取当前时间。

通过NTP实现

 //NTP消息大小摘要是16字节 (RFC 2030)
 byte[] ntpData = new byte[48];
 //设置跳跃指示器、版本号和模式值
 // LI = 0 (no warning), VN = 3 (IPv4 only), Mode = 3 (Client Mode)
 ntpData[0] = 0x1B; 
 IPAddress ip = iPAddress;
 // NTP服务给UDP分配的端口号是123
 IPEndPoint ipEndPoint = new IPEndPoint(ip, 123);
 // 使用UTP进行通讯
 Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
 socket.Connect(ipEndPoint);
 socket.ReceiveTimeout = 3000;
 socket.Send(ntpData);
 socket.Receive(ntpData);
 socket?.Close();
 socket?.Dispose();

程序手动输入。

2. 转换为本地时间

 //传输时间戳字段偏移量，以64位时间戳格式，应答离开客户端服务器的时间
 const byte serverReplyTime = 40;
 // 获得秒的部分
 ulong intPart = BitConverter.ToUInt32(ntpData, serverReplyTime);
 //获取秒的部分
 ulong fractPart = BitConverter.ToUInt32(ntpData, serverReplyTime + 4);
 //由big-endian 到 little-endian的转换
 intPart = swapEndian(intPart);
 fractPart = swapEndian(fractPart);
 ulong milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000UL);
 // UTC时间
 DateTime webTime = (new DateTime(1900, 1, 1, 0, 0, 0, DateTimeKind.Utc)).AddMilliseconds(milliseconds);
 //本地时间
 DateTime dt = webTime.ToLocalTime();

3. 获取当前是否是管理员

public static bool IsAdministrator()
    {
      WindowsIdentity identity = WindowsIdentity.GetCurrent();
      WindowsPrincipal principal = new WindowsPrincipal(identity);
      return principal.IsInRole(WindowsBuiltInRole.Administrator);
    }

4. 引入dll

[DllImport("kernel32.dll")]
private static extern bool SetLocalTime(ref Systemtime time);
 
//转化后的时间进行本地设置，并返回成功与否
bool isSuccess = SetLocalDateTime(dt);

5. 提升权限

如果程序不是管理员身份运行则不可以设置时间

引入引用程序清单文件（app.manifest），步骤：添加新建项->选择‘应用程序清单文件（仅限windows）'

引入后再文件中出现app.manifest文件

Value	Description	Comment
asInvoker	The application runs with the same access token as the parent process.	Recommended for standard user applications. Do refractoring with internal elevation points, as per the guidance provided earlier in this document.
highestAvailable	The application runs with the highest privileges the current user can obtain.	Recommended for mixed-mode applications. Plan to refractor the application in a future release.
requireAdministrator	The application runs only for administrators and requires that the application be launched with the full access token of an administrator.	Recommended for administrator only applications. Internal elevation points

默认权限：

 <requestedExecutionLevel level="asInvoker " uiAccess="false" />

asInvoker 表示当前用户本应该具有的权限

highestAvailable 表示提升当前用户最高权限

requireAdministrator 表示提升为管理员权限

修改权限：

 <requestedExecutionLevel level="requireAdministrator" uiAccess="false" />

6. 重新生成程序

源码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
 
namespace WindowsFormsApp1
{
 
  public class DateTimeSynchronization
  {
    [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;
    }
 
    [DllImport("kernel32.dll")]
    private static extern bool SetLocalTime(ref Systemtime time);
 
    private static uint swapEndian(ulong x)
    {
      return (uint)(((x & 0x000000ff) << 24) +
      ((x & 0x0000ff00) << 8) +
      ((x & 0x00ff0000) >> 8) +
      ((x & 0xff000000) >> 24));
    }
 
    /// <summary>
    /// 设置系统时间
    /// </summary>
    /// <param name="dt">需要设置的时间</param>
    /// <returns>返回系统时间设置状态，true为成功，false为失败</returns>
    private static bool SetLocalDateTime(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;
    }
    private static IPAddress iPAddress = null;
    public static bool Synchronization(string host, out DateTime syncDateTime, out string message)
    {
      syncDateTime = DateTime.Now;
      try
      {
        message = "";
        if (iPAddress == null)
        {
          var iphostinfo = Dns.GetHostEntry(host);
          var ntpServer = iphostinfo.AddressList[0];
          iPAddress = ntpServer;
        }
        DateTime dtStart = DateTime.Now;
        //NTP消息大小摘要是16字节 (RFC 2030)
        byte[] ntpData = new byte[48];
        //设置跳跃指示器、版本号和模式值
        // LI = 0 (no warning), VN = 3 (IPv4 only), Mode = 3 (Client Mode)
        ntpData[0] = 0x1B; 
        IPAddress ip = iPAddress;
        // NTP服务给UDP分配的端口号是123
        IPEndPoint ipEndPoint = new IPEndPoint(ip, 123);
        // 使用UTP进行通讯
        Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
        socket.Connect(ipEndPoint);
        socket.ReceiveTimeout = 3000;
        socket.Send(ntpData);
        socket.Receive(ntpData);
        socket?.Close();
        socket?.Dispose();
        DateTime dtEnd = DateTime.Now;
        //传输时间戳字段偏移量，以64位时间戳格式，应答离开客户端服务器的时间
        const byte serverReplyTime = 40;
        // 获得秒的部分
        ulong intPart = BitConverter.ToUInt32(ntpData, serverReplyTime);
        //获取秒的部分
        ulong fractPart = BitConverter.ToUInt32(ntpData, serverReplyTime + 4);
        //由big-endian 到 little-endian的转换
        intPart = swapEndian(intPart);
        fractPart = swapEndian(fractPart);
        ulong milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000UL);
        // UTC时间
        DateTime webTime = (new DateTime(1900, 1, 1, 0, 0, 0, DateTimeKind.Utc)).AddMilliseconds(milliseconds);
        //本地时间
        DateTime dt = webTime.ToLocalTime();
        bool isSuccess = SetLocalDateTime(dt);
        syncDateTime = dt;
 
      }
      catch (Exception ex)
      {
        message = ex.Message;
        return false;
      }
      return true;
 
    }
  }
}