C#程序中获取百度时间

        /// <summary>
        /// 获取百度时间
        /// </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 = 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

            var aaa = GetNetDateTime();
            var bbb = Convert.ToDateTime(aaa).ToString("yyyy-MM-dd HH:mm:ss");
            textBox2.Text = bbb;

测试步骤：

1、在电脑右下角鼠标右键选择“调整日期和时间”

2、关闭“自动设置时间”，点击下发“更改”

 3、手动设置一个和当前时间不一致的时间用来测试

4、打开程序，测试即可看到系统时间与电脑时间一致，百度时间与百度查询的时间一致（百度查询时间链接：现在北京时间 在线标准北京时间校对 (beijing-time.org)）