向服务提供者公开Java服务提供者接口(Expose a Java Service Provider Interface to Service Providers)

 现有答案中有很好的信息，但让我尝试一个实用的总结： 
 
 System.DateTime.ToFileTime()和System.DateTime.ToFileTimeUtc()之间的区别唯一重要的是当实例的.Kind属性等于Unspecified ，即，如果不清楚时间值是表示本地时间还是UTC时间。 
 这个信息实际上是Hans Passant的一个答案，他自己删除了。 
 
 换句话说：对于其.Kind属性等于Local或Utc （唯一其他可能的值）的System.DateTime实例， System.DateTime.ToFileTime()和System.DateTime.ToFileTimeUtc()行为相同 - 这是OP经历的，因为他的输入值是.Kind Local （ File.GetCreationTime()返回的那种）。 
 
 请注意，设计的相关System.DateTimeOffset类型始终带有显式时区信息，因此从不存在歧义，这就是为什么该类型只有 .ToFileTime()方法。 
 
 正如其他人所说， 返回值始终代表UTC时间 ： 
 
 
 
 根据定义，文件时间值总是表示UTC中的时间点。 
 
 
 因此， .ToFileTime()和.ToFileTimeUtc()创建一个时间点，表示为自1601年1月1日午夜以来100ns间隔的计数。 
 
 
 为了补充OP自己的例子，其中.ToFileTime()和.ToFileTimeUtc()的结果不同： 
 
// Create a DateTime instance with .Kind equal to Unspecified;
// use the earliest date that can be represented as a file time.
DateTime dtUnspecified = DateTime.Parse("1601-01-01");

Console.WriteLine(
    dtUnspecified.ToFileTime() + "\n" +
    dtUnspecified.ToFileTimeUtc()
);
 
 美国东部时区的样本输出： 
 
180000000000  // 1601-01-01T05:00:00Z - 5 AM UTC
0             // 1601-01-01T00:00:00Z - midnight UTC

There's good information in the existing answers, but let me attempt a pragmatic summary:
 
The only time the distinction between System.DateTime.ToFileTime() and System.DateTime.ToFileTimeUtc() matters is when the instance's .Kind property equals Unspecified, i.e., if it's unclear whether the time value represents a local or UTC time.
 This information was actually in an answer by Hans Passant that he himself deleted.
 
In other word: for System.DateTime instances whose .Kind property equals either Local or Utc (the only other possible values), System.DateTime.ToFileTime() and System.DateTime.ToFileTimeUtc() behave identically - this is what the OP experienced, because his input value was of .Kind Local (the kind returned by File.GetCreationTime()).
 
Note that the related System.DateTimeOffset type by design always carries explicit time zone information, so there's never ambiguity, which is why that type only has a .ToFileTime() method.
 
As others have noted, the return value always represents a UTC time:
 
 
 
File time values by definition, invariably represent a point in time in UTC.
 
 
Thus, both .ToFileTime() and .ToFileTimeUtc() create a point in time expressed as the count of 100ns intervals since midnight January 1, 1601 UTC.
 
 
To complement the OP's own example with one where .ToFileTime() and .ToFileTimeUtc() do differ in outcome:
 
// Create a DateTime instance with .Kind equal to Unspecified;
// use the earliest date that can be represented as a file time.
DateTime dtUnspecified = DateTime.Parse("1601-01-01");

Console.WriteLine(
    dtUnspecified.ToFileTime() + "\n" +
    dtUnspecified.ToFileTimeUtc()
);
 
Sample output in the US Eastern time zone:
 
180000000000  // 1601-01-01T05:00:00Z - 5 AM UTC
0             // 1601-01-01T00:00:00Z - midnight UTC