这里有一个示例代码,但是它开始讨论毫秒/纳秒的问题。
同样的问题出现在MSDN上,从c#的Unix时代开始。
这是我目前得到的:
public Double CreatedEpoch
{
get
{
DateTime epoch = new DateTime(1970, 1, 1, 0, 0, 0, 0).ToLocalTime();
TimeSpan span = (this.Created.ToLocalTime() - epoch);
return span.TotalSeconds;
}
set
{
DateTime epoch = new DateTime(1970, 1, 1, 0, 0, 0, 0).ToLocalTime();
this.Created = epoch.AddSeconds(value);
}
}
对于。net 4.6及更高版本:
public static class UnixDateTime
{
public static DateTimeOffset FromUnixTimeSeconds(long seconds)
{
if (seconds < -62135596800L || seconds > 253402300799L)
throw new ArgumentOutOfRangeException("seconds", seconds, "");
return new DateTimeOffset(seconds * 10000000L + 621355968000000000L, TimeSpan.Zero);
}
public static DateTimeOffset FromUnixTimeMilliseconds(long milliseconds)
{
if (milliseconds < -62135596800000L || milliseconds > 253402300799999L)
throw new ArgumentOutOfRangeException("milliseconds", milliseconds, "");
return new DateTimeOffset(milliseconds * 10000L + 621355968000000000L, TimeSpan.Zero);
}
public static long ToUnixTimeSeconds(this DateTimeOffset utcDateTime)
{
return utcDateTime.Ticks / 10000000L - 62135596800L;
}
public static long ToUnixTimeMilliseconds(this DateTimeOffset utcDateTime)
{
return utcDateTime.Ticks / 10000L - 62135596800000L;
}
[Test]
public void UnixSeconds()
{
DateTime utcNow = DateTime.UtcNow;
DateTimeOffset utcNowOffset = new DateTimeOffset(utcNow);
long unixTimestampInSeconds = utcNowOffset.ToUnixTimeSeconds();
DateTimeOffset utcNowOffsetTest = UnixDateTime.FromUnixTimeSeconds(unixTimestampInSeconds);
Assert.AreEqual(utcNowOffset.Year, utcNowOffsetTest.Year);
Assert.AreEqual(utcNowOffset.Month, utcNowOffsetTest.Month);
Assert.AreEqual(utcNowOffset.Date, utcNowOffsetTest.Date);
Assert.AreEqual(utcNowOffset.Hour, utcNowOffsetTest.Hour);
Assert.AreEqual(utcNowOffset.Minute, utcNowOffsetTest.Minute);
Assert.AreEqual(utcNowOffset.Second, utcNowOffsetTest.Second);
}
[Test]
public void UnixMilliseconds()
{
DateTime utcNow = DateTime.UtcNow;
DateTimeOffset utcNowOffset = new DateTimeOffset(utcNow);
long unixTimestampInMilliseconds = utcNowOffset.ToUnixTimeMilliseconds();
DateTimeOffset utcNowOffsetTest = UnixDateTime.FromUnixTimeMilliseconds(unixTimestampInMilliseconds);
Assert.AreEqual(utcNowOffset.Year, utcNowOffsetTest.Year);
Assert.AreEqual(utcNowOffset.Month, utcNowOffsetTest.Month);
Assert.AreEqual(utcNowOffset.Date, utcNowOffsetTest.Date);
Assert.AreEqual(utcNowOffset.Hour, utcNowOffsetTest.Hour);
Assert.AreEqual(utcNowOffset.Minute, utcNowOffsetTest.Minute);
Assert.AreEqual(utcNowOffset.Second, utcNowOffsetTest.Second);
Assert.AreEqual(utcNowOffset.Millisecond, utcNowOffsetTest.Millisecond);
}
}
为了补充ScottCher的回答,我最近发现自己遇到了一种令人讨厌的情况,即在输入数据集中将秒级和毫秒级的UNIX时间戳任意混合在一起。下面的代码似乎可以很好地处理这个问题:
static readonly DateTime UnixEpoch = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
static readonly double MaxUnixSeconds = (DateTime.MaxValue - UnixEpoch).TotalSeconds;
public static DateTime UnixTimeStampToDateTime(double unixTimeStamp)
{
return unixTimeStamp > MaxUnixSeconds
? UnixEpoch.AddMilliseconds(unixTimeStamp)
: UnixEpoch.AddSeconds(unixTimeStamp);
}
. net的最新版本(v4.6)增加了对Unix时间转换的内置支持。这包括以秒或毫秒表示的到Unix时间和从Unix时间。
Unix时间(秒到UTC DateTimeOffset):
DateTimeOffset dateTimeOffset = DateTimeOffset.FromUnixTimeSeconds(1000);
DateTimeOffset到Unix时间(单位:秒):
long unixTimeStampInSeconds = dateTimeOffset.ToUnixTimeSeconds();
Unix时间(单位:毫秒)到UTC DateTimeOffset:
DateTimeOffset dateTimeOffset = DateTimeOffset.FromUnixTimeMilliseconds(1000000);
DateTimeOffset到Unix时间(单位:毫秒):
long unixTimeStampInMilliseconds = dateTimeOffset.ToUnixTimeMilliseconds();
注意:这些方法转换为UTC DateTimeOffset。要获得一个DateTime表示,只需使用DateTimeOffset。UtcDateTime或DateTimeOffset。LocalDateTime属性:
DateTime dateTime = dateTimeOffset.UtcDateTime;
DateTime unixEpoch = DateTime.ParseExact("1970-01-01", "yyyy-MM-dd", System.Globalization.CultureInfo.InvariantCulture);
DateTime convertedTime = unixEpoch.AddMilliseconds(unixTimeInMillisconds);
当然,可以将unixEpoch设置为全局静态,这样它只需要在项目中出现一次,如果UNIX时间以秒为单位,则可以使用AddSeconds。
反过来说:
double unixTimeInMilliseconds = timeToConvert.Subtract(unixEpoch).TotalMilliseconds;
截断为Int64和/或根据需要使用TotalSeconds。