C# 時間戳和日期相互轉換

1.日期轉換為時間戳Timestamp

        /// <summary>
        /// 日期轉換為時間戳Timestamp
        /// </summary>
        /// <param name="dateTime">要轉換的日期</param>
        /// <returns></returns>
        public static long GetTimeStamp(DateTime dateTime)
        {
            DateTime _dtStart = new DateTime(1970, 1, 1, 8, 0, 0);
            //10位的時間戳
            long timeStamp = Convert.ToInt32(dateTime.Subtract(_dtStart).TotalSeconds);
            //13位的時間戳
            //long timeStamp = Convert.ToInt64(dateTime.Subtract(_dtStart).TotalMilliseconds);
            return timeStamp;
        }

2.時間戳轉換為時間

        /// <summary>
        /// UTC時間戳Timestamp轉換為北京時間
        /// </summary>
        /// <param name="timestamp">要轉換的時間戳</param>
        /// <returns></returns>
        public static DateTime GetDateTime(long timestamp)
        {
            //DateTime dtStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1)); 
            //使用上面的方式會顯示TimeZone已過時
            DateTime dtStart = TimeZoneInfo.ConvertTime(new DateTime(1970, 1, 1), TimeZoneInfo.Local);
            long lTime = long.Parse(timestamp + "0000000");
            TimeSpan timeSpan = new TimeSpan(lTime);
            DateTime targetDt = dtStart.Add(timeSpan).AddHours(8);
            return targetDt;
        }

3.日期轉換公共類

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WeChatDemo.Common
{
    public class DateTimeHelper
    {
        /// <summary>
        /// 日期轉換為時間戳Timestamp
        /// </summary>
        /// <param name="dateTime">要轉換的日期</param>
        /// <returns></returns>
        public static long GetTimeStamp(DateTime dateTime)
        {
            DateTime _dtStart = new DateTime(1970, 1, 1, 8, 0, 0);
            //10位的時間戳
            long timeStamp = Convert.ToInt32(dateTime.Subtract(_dtStart).TotalSeconds);
            //13位的時間戳
            //long timeStamp = Convert.ToInt64(dateTime.Subtract(_dtStart).TotalMilliseconds);
            return timeStamp;
        }

        /// <summary>
        /// UTC時間戳Timestamp轉換為北京時間
        /// </summary>
        /// <param name="timestamp">要轉換的時間戳</param>
        /// <returns></returns>
        public static DateTime GetDateTime(long timestamp)
        {
            //DateTime dtStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1)); 
            //使用上面的方式會顯示TimeZone已過時
            DateTime dtStart = TimeZoneInfo.ConvertTime(new DateTime(1970, 1, 1), TimeZoneInfo.Local);
            long lTime = long.Parse(timestamp + "0000000");
            TimeSpan timeSpan = new TimeSpan(lTime);
            DateTime targetDt = dtStart.Add(timeSpan).AddHours(8);
            return targetDt;
        }
    }
}