c#将电脑时间同步到网络时间

最近遇到个项目，需要控制软件使用时间，由于电脑不联网可以修改时间，故需要联网使电脑同步网络时间

网上寻找了很多解决方案，代码如下：

//Forproc_Win32.cs
//对常用Win32 API函数及结构的声明
using System;
using System.Runtime.InteropServices;
 
namespace Farproc.Win32
{
    /// <summary>
    ///
    /// </summary>
    public 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();
        }
    }
 public class Win32API
    {
        [DllImport("Kernel32.dll")]
        public static extern bool SetLocalTime( ref SYSTEMTIME Time );
        [DllImport("Kernel32.dll")]
        public static extern void GetLocalTime(ref SYSTEMTIME Time);
    }
}
private void button1_Click(object sender, System.EventArgs e)
{
    //取得当前系统时间
    DateTime t = DateTime.Now;
    //在当前时间上加上一周
    t = t.AddDays(7);
    //转换System.DateTime到SYSTEMTIME
    SYSTEMTIME st = new SYSTEMTIME();
    st.FromDateTime(t);
    //调用Win32 API设置系统时间
    Win32API.SetLocalTime(ref st);
    //显示当前时间
    MessageBox.Show(DateTime.Now.ToString());
}

试过很多次，都没能正确修改。

后来突发奇想，cmd不是能修改系统时间吗？

然后用cmd命令成功实现了功能。

/// <summary>  
        /// 获取网络日期时间  
        /// </summary>  
        /// <returns></returns>  
        public static string GetNetDateTime()
        {
            WebRequest request = null;
            WebResponse response = null;
            WebHeaderCollection headerCollection = null;
            string datetime = string.Empty;
            try
            {
                request = WebRequest.Create("https://www.baidu.com");
                request.Timeout = 3000;
                request.Credentials = CredentialCache.DefaultCredentials;
                response = (WebResponse)request.GetResponse();
                headerCollection = response.Headers;
                foreach (var h in headerCollection.AllKeys)
                { if (h == "Date") { datetime = headerCollection[h]; } }
                return datetime;
            }
            catch (Exception) { return datetime; }
            finally
            {
                if (request != null)
                { request.Abort(); }
                if (response != null)
                { response.Close(); }
                if (headerCollection != null)
                { headerCollection.Clear(); }
            }
        }

//调用cmd修改系统时间
        public static void setSystemTime(DateTime netTime)
        {
            System.Diagnostics.Process p = new System.Diagnostics.Process();
            p.StartInfo.FileName = "cmd.exe";
            p.StartInfo.UseShellExecute = false; //是否使用操作系统shell启动
            p.StartInfo.RedirectStandardInput = true;//接受来自调用程序的输入信息
            p.StartInfo.RedirectStandardOutput = true;//由调用程序获取输出信息
            p.StartInfo.RedirectStandardError = true;//重定向标准错误输出
            p.StartInfo.CreateNoWindow = true;//不显示程序窗口
            p.Start();//启动程序

string dtdate = netTime.ToString("yyyy-MM-dd");//获取日期
            string dttime = netTime.ToString("HH:mm:ss");//获取时间
            string dos1 = "date " + dtdate;//命令1
            string dos2 = "time " + dttime;//命令2
            p.StandardInput.WriteLine(dos1 + "&" + dos2 + "&exit");
            p.StandardInput.AutoFlush = true;
            string output = p.StandardOutput.ReadToEnd();
            p.WaitForExit();//等待程序执行完退出进程
            p.Close();
        }