客户的机器的系统时间经常出错，导致给他们做的软件无法正常使用，所以后来就加了一个同步网络时间的小功能。实现起来很简单，但是却很使用。这个小功能就是先获取网络时间，然后将系统的时间修改成从网络获得的时间。下面是具体的实现：

获取网络时间： 

using System;  
using System.Collections.Generic;  
using System.Linq;  
using System.Text;  
using System.IO;  
using System.Net;  
using System.Net.Sockets;  
using System.Text.RegularExpressions;  
using System.Runtime.InteropServices;
using System.Runtime;    



    /// <summary>  
    /// 网络时间  
    /// </summary>  
    public class NetTime
    {
       
        /// <summary>  
        /// 获取标准北京时间，读取http://www.beijing-time.org/time.asp  
        /// </summary>  
        /// <returns>返回网络时间</returns>  
        public DateTime GetBeijingTime()
        {
         
            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("\r\n", "");
                }

                string year = tempArray[1].Split('=')[1];
                string month = tempArray[2].Split('=')[1];
                string day = tempArray[3].Split('=')[1];
                string hour = tempArray[5].Split('=')[1];
                string minite = tempArray[6].Split('=')[1];
                string second = tempArray[7].Split('=')[1];

                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;

        }
    }


 

获取网络时间，返回一个DateTime对象，然后传给设置系统时间的方法，修改系统时间。
同步系统时间：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text.RegularExpressions;
using System.Runtime.InteropServices;
using System.Runtime;    


    /// <summary>
    /// 更新系统时间
    /// </summary>
    public class UpdateTime
    {
        //设置系统时间的API函数
        [DllImport("kernel32.dll")]
        private static extern bool SetLocalTime(ref SYSTEMTIME time);

        [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;
        }

        /// <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>
        public static bool SetDate(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;
        }
    }


 

两个方法分别写在了两个类里面，只需要在客户端实例化两个对象，然后依次调用其方法即可，简单实用。