Remove leading zeros from time to show elapsed time

Question

I need to display simplest version of elapsed time span. Is there any ready thing to do that?

Samples:

HH:mm:ss
10:43:27 > 10h43m27s
00:04:12 > 4m12s
00:00:07 > 7s

I think I need a format provider for elapsed time.

Answer 1

You can use string.Format to achieve this, along with some conditional statements:

public static string GetSimplestTimeSpan(TimeSpan timeSpan)
{
    var result = string.Empty;
    if (timeSpan.Days > 0)
    {
        result += string.Format(
            @"{0:ddd\d}", timeSpan).TrimStart('0');
    }
    if (timeSpan.Hours > 0)
    {
        result += string.Format(
            @"{0:hh\h}", timeSpan).TrimStart('0');
    }
    if (timeSpan.Minutes > 0)
    {
        result += string.Format(
            @"{0:mm\m}", timeSpan).TrimStart('0');
    }
    if (timeSpan.Seconds > 0)
    {
        result += string.Format(
            @"{0:ss\s}", timeSpan).TrimStart('0');
    }
    return result;
}

Though, seeing the answer by BrokenGlass I'm tempted to say using Format here at all is overkill. However, it does allow you to tweak the output of each element of the elapsed time span if required.

Answer 2

Simple extension method should be enough:

static class Extensions
{ 
    public static string ToShortForm(this TimeSpan t)
    {
        string shortForm = "";
        if (t.Hours > 0)
        {
            shortForm += string.Format("{0}h", t.Hours.ToString());
        }
        if (t.Minutes > 0)
        {
            shortForm += string.Format("{0}m", t.Minutes.ToString());
        }
        if (t.Seconds > 0)
        {
            shortForm += string.Format("{0}s", t.Seconds.ToString());
        }
        return shortForm;
    } 
} 

Test it with:

TimeSpan tsTest = new TimeSpan(10, 43, 27);
string output = tsTest.ToShortForm();
tsTest = new TimeSpan(0, 4, 12);
output = tsTest.ToShortForm();
tsTest = new TimeSpan(0, 0, 7);
output = tsTest.ToShortForm();

Answer 3

Here's a one-liner (almost), assuming you have the TimeSpan objectL

(new TimeSpan(0, 0, 30, 21, 3))
  .ToString(@"d\d\ hh\hmm\mss\s")
  .TrimStart(' ','d','h','m','s','0');

The sample code outputs

30m21s

The first line just makes a TimeSpan object for the sake of an example, .ToString formats it in the format you're asking for and then .TrimStart removes the leading characters you don't need.

Answer 4

I don't think this can be done in a straightforward way doing a custom format serializer - I'd just roll my own:

TimeSpan delta = TimeSpan.Parse("09:03:07");
string displayTime = string.Empty;
if (delta.Hours > 0)
    displayTime += delta.Hours.ToString() + "h";

if (delta.Minutes > 0)
    displayTime += delta.Minutes.ToString() + "m";

if (delta.Seconds > 0)
    displayTime += delta.Seconds.ToString() + "s";

Note that this would only work for positive time spans.