/// <summary>

/// 日期转换成unix时间戳

/// </summary>

/// <param name="dateTime"></param>

/// <returns></returns>

public static long DateTimeToUnixTimestamp(DateTime dateTime)

{

    var start = new DateTime(1970, 1, 1, 0, 0, 0, dateTime.Kind);

    return Convert.ToInt64((dateTime - start).TotalSeconds);

}

/// <summary>

/// unix时间戳转换成日期

/// </summary>

/// <param name="unixTimeStamp">时间戳（秒）</param>

/// <returns></returns>

public static DateTime UnixTimestampToDateTime(this DateTime target, long timestamp)

{

    var start = new DateTime(1970, 1, 1, 0, 0, 0, target.Kind);

    return start.AddSeconds(timestamp);

}

/// <summary>

        /// unix时间戳转换成日期

        /// </summary>

        /// <param name="unixTimeStamp">时间戳（秒）</param>

        /// <returns></returns>

        public static DateTime UnixTimestampToDateTime(long timestamp)

        {

            var start = new DateTime(1970, 1, 1, 8, 0, 0, DateTimeKind.Unspecified);

            return start.AddMilliseconds(timestamp);

        }