How to compare time part of datetime

问题

Let's say we have

DateTime t1 = DateTime.Parse("2012/12/12 15:00:00.000");

and

DateTime t2 = DateTime.Parse("2012/12/12 15:03:00.000");

How to compare it in C# and say which time is "is later than"?

回答1:

You can use the TimeOfDay property and use the Compare against it.

TimeSpan.Compare(t1.TimeOfDay, t2.TimeOfDay)

Per the documentation:

-1  if  t1 is shorter than t2.
0   if  t1 is equal to t2.
1   if  t1 is longer than t2.

回答2:

The <, <=, >, >=, == operators all work directly on DateTime and TimeSpan objects. So something like this works:

DateTime t1 = DateTime.Parse("2012/12/12 15:00:00.000");
DateTime t2 = DateTime.Parse("2012/12/12 15:03:00.000");

if(t1.TimeOfDay > t2.TimeOfDay) {
    //something
}
else {
    //something else
}

回答3:

Use the DateTime.Compare method:

DateTime date1 = new DateTime(2009, 8, 1, 0, 0, 0);
DateTime date2 = new DateTime(2009, 8, 1, 12, 0, 0);
int result = DateTime.Compare(date1, date2);
string relationship;

if (result < 0)
   relationship = "is earlier than";
else if (result == 0)
   relationship = "is the same time as";         
else
   relationship = "is later than";

Console.WriteLine("{0} {1} {2}", date1, relationship, date2);

Edit: If you just want to compare the times, and ignore the date, you can use the TimeOfDay as others have suggested. If you need something less fine grained, you can also use the Hour and Minute properties.

来源：https://stackoverflow.com/questions/10290187/how-to-compare-time-part-of-datetime

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.net

datetime

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