C#时间戳转换[转发]

/// <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);
        }