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.NET 4 Baby Steps - Part I: TimeSpan

Robert MacLean
3 May 2010

SNC00025Welcome to part one of a new series of blog posts which will cover what is new in .NET 4. To be different I am not looking at the big features, like WF 4 or the super cool parallel stuff. This series will cover the smaller features, like new methods on existing classes or whole new classes which have been added. As with all series I do, you can see the rest of the post in the series on the series index.

We’ll start off with TimeSpan, which has been around since .NET 1.0 and represents a time interval (duration of time or elapsed time) that is measured as a positive or negative number of days, hours, minutes, seconds, and fractions of a second. So what is new in TimeSpan for .NET 4?

Parse & TryParse

Parse & TryParse are methods which have been around since the beginning and let you input a string in a specific format [-][d’.’]hh’:’mm’:’ss[‘.’fffffff]. and get a TimeSpan object back. For example:

TimeSpan oneFranctionSecond = TimeSpan.Parse("0.00:00:00.1");
TimeSpan oneHour = TimeSpan.Parse("1:00");
TimeSpan oneThousandDaysPast = TimeSpan.Parse("-1000.00:00");
Console.WriteLine(oneFranctionSecond);
Console.WriteLine(oneHour);
Console.WriteLine(oneThousandDaysPast);

This produces: image

What is new in parsing? The ability to add in culture information through IFormatProvider. Why is this important? Because not everyone formats numbers the same. For example:

CultureInfo us = CultureInfo.GetCultureInfo("en-us"); // America
CultureInfo rm = CultureInfo.GetCultureInfo("rm"); // No idea, but it has my initials ;)
CultureInfo za = CultureInfo.GetCultureInfo("en-za"); // South Africa

string usResult = string.Format(us, "{0:N}", 100000);
string rmResult = string.Format(rm, "{0:N}", 100000);
string zaResult = string.Format(za, "{0:N}", 100000);

Console.WriteLine("America:\t {0}", usResult);
Console.WriteLine("RM:\t\t {0}", rmResult);
Console.WriteLine("South Africa:\t {0}", zaResult);
Produces: image

See how all three locations have different formats, and this is important because the old methods couldn’t cope with these differences in numbers - they could only accept a single specific format.

Now we can do the following:

CultureInfo us = CultureInfo.GetCultureInfo("en-us"); // America
CultureInfo ru = CultureInfo.GetCultureInfo("ru-RU"); // Russia

TimeSpan oneFranctionSecondUS = TimeSpan.Parse("6:12:14:45.3448", us);
TimeSpan oneFranctionSecondRU = TimeSpan.Parse("6:12:14:45,3448", ru);

Console.WriteLine(oneFranctionSecondUS);
Console.WriteLine(oneFranctionSecondRU);

Note the comma in the Russian formatting, if you tried this in .NET 3.5 or before you would’ve gotten a FormatException but now it works!

ParseExact & TryParseExact

These are two brand new methods which let us specify the format string to use. Until now we have had to make sure we complied with: [-][d’.’]hh’:’mm’:’ss[‘.’fffffff].

Now we do not need to comply with a single format. We have two options with the format string either a build in one or a custom one. The built in ones are:

  • c/t/T : These three do the same and this is what we are used to currently, namely: [-][d’.’]hh’:’mm’:’ss[‘.’fffffff].
    • Examples:
      • TimeSpan.Zero -> 00:00:00
      • New TimeSpan(0, 0, 30, 0) -> 00:30:00
      • New TimeSpan(3, 17, 25, 30, 500) -> 3.17:25:30.5000000
  • g: The cultural sensitive short format. This is basically the same as c but the format provider supplied will be respected where c ignores it: [-][d’:’]h’:’mm’:’ss[.FFFFFFF].
    • Examples:
      • New TimeSpan(1, 3, 16, 50, 500) -> 1:3:16:50.5 (en-US)
      • New TimeSpan(1, 3, 16, 50, 500) -> 1:3:16:50,5 (fr-FR)
      • New TimeSpan(1, 3, 16, 50, 599) -> 1:3:16:50.599 (en-US)
      • New TimeSpan(1, 3, 16, 50, 599) -> 1:3:16:50,599 (fr-FR)
  • G: The cultural sensitive long format in which there is no optional items, except the negative symbol: [-]d’:’hh’:’mm’:’ss.fffffff.
    • Examples:
    • New TimeSpan(18, 30, 0) -> 0:18:30:00.0000000 (en-US)
    • New TimeSpan(18, 30, 0) -> 0:18:30:00,0000000 (fr-FR)

We also have custom ones now, so we can really tweak it and this will be great for interoperability. I am not going to list all the parts as there is a lot, but every individual component is covered. Some examples of what we can now do are:

TimeSpan oneFranctionSecond = TimeSpan.ParseExact("1", "%F", CultureInfo.CurrentCulture);
TimeSpan oneMinuteThirtySeconds = TimeSpan.ParseExact("1:30", @"%m\:%s", CultureInfo.CurrentCulture);
TimeSpan oneDay = TimeSpan.ParseExact("1", "%d", CultureInfo.CurrentCulture);
TimeSpan oneDayAndTwoHours = TimeSpan.ParseExact("1=2", @"%d\=%h", CultureInfo.CurrentCulture);            

Console.WriteLine(oneFranctionSecond);
Console.WriteLine(oneMinuteThirtySeconds);
Console.WriteLine(oneDay);
Console.WriteLine(oneDayAndTwoHours);
Which produces: image
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