Handle negative time spans

问题

In my output of a grid, I calculate a TimeSpan and take its TotalHours. e.g.

(Eval("WorkedHours") - Eval("BadgedHours")).TotalHours

The goal is to show the TotalHours as 39:44, so I need to convert the value from 7.5 to 07:30. This is no problem... unless it's negative!

I can create a TimeSpan object from Hours with

TimeSpan.FromHours( (Eval("WorkedHours") - Eval("BadgedHours")).TotalHours)

If it's negative, I can't convert it to a DateTime to use the .ToString("HH:mm") method, and the TimeSpan object does not support the format string.

回答1:

Isn't there a TimeSpan.Duration method? I think this would handle what you are trying to do.

回答2:

static string ToHMString(TimeSpan timespan) { 
    if (timespan.Ticks < 0) return "-" + ToHMString(timespan.Negate());

    return timespan.TotalHours.ToString("#0") + ":" + timespan.Minutes.ToString("00");
}

Console.WriteLine(ToHMString(TimeSpan.FromHours(3)));       //Prints "3:00"
Console.WriteLine(ToHMString(TimeSpan.FromHours(-27.75)));  //Prints "-28:45"

This will also work correctly if the timespan is longer than 24 hours.

回答3:

Just multiply it by -1 or use an absolute value function.

回答4:

There is a Negate method in the TimeSpan class.

Link to the MSDN documentation: TimeSpan.Negate Method()

回答5:

its working .try this

mytimespam.Negate();

回答6:

The simple solution would be to do:

string format = "HH:mm";
if(hours < 0)
  format = "-" + format;

hours = Math.Abs(hours)

回答7:

Hi i worked this into a bit of code i have been writing, hope it helps

(results) is an int variable

(TimeSpan.FromMinutes(result)) < TimeSpan.Zero ? "-" + TimeSpan.FromMinutes(result).ToString(@"hh\:mm") : "" + TimeSpan.FromMinutes(result).ToString(@"hh\:mm");

回答8:

I checked to every where.But i didnt get a correct answer that why i used this way to finish

TimeSpan diff = actualout.Subtract(actualin);
 string a =(diff.ToString()).ToString();
if(a.Contains("-"))
 {        
 diff = new TimeSpan(0,0,0,0);
}

回答9:

TimeSpan Diff = Date1 - Date2;

if ((int)Diff.TotalDays < 0) { // your code }

来源：https://stackoverflow.com/questions/1018643/handle-negative-time-spans

标签

.net

datetime

timespan