We Keep Coding

Using a clock in/out timer and displaying the time elapsed

I have an application that is supposed to simulate an employee clocking in and out of work. Clicking clock in will start a timer, and when clock out is clicked, it will end the timer and display how much time is elapsed in the result boxes below. This is probably a really simple task for most people, but I don't have a lot of knowledge or experience with using dates, times, timers, etc., so I don't know what to code for this.

I would recommend you check out the stopwatch class for C#. As you can see in the example below, the format comes out as Hours, Minutes, Seconds, Milliseconds, you could then parse that outputted string to display appropriately inside your timeclock visual. I hope that helps!
Here is a link to the relevant documentation
using System;
using System.Diagnostics;
using System.Threading;
class Program
{
static void Main(string[] args)
{
Stopwatch stopWatch = new Stopwatch();
stopWatch.Start();
Thread.Sleep(10000);
stopWatch.Stop();
// Get the elapsed time as a TimeSpan value.
TimeSpan ts = stopWatch.Elapsed;
// Format and display the TimeSpan value.
string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}",
ts.Hours, ts.Minutes, ts.Seconds,
ts.Milliseconds / 10);
Console.WriteLine("RunTime " + elapsedTime);
}
}

For the purpose of a time clock I would use the DateTime. This way you'll have the date and time of your clock punches. Simply call DateTime.Now for in/out and read the TimeSpan parameters as needed.
DateTime clockIn = new DateTime(2020, 02, 12, 8, 0, 0);
DateTime clockOut = new DateTime(2020, 02, 12, 16, 30, 0);
TimeSpan timeWorked = clockOut - clockIn;
// Time worked = 8 hours, 30 minutes
string timeWorkedReport = $"Time worked = {timeWorked.Hours} hours, {timeWorked.Minutes} minutes";

C# TimeSpan.Milliseconds formated to 2 digits

I have a timer that I want to show minutes:seconds:hundreds of seconds.
Since C# timespan doesn't have a method to get hundreds but only milliseconds, I need to somehow format this.
TimeSpan ts = stopWatch.Elapsed;
currentTime = String.Format("{0:00}:{1:00}:{2:00}", ts.Minutes, ts.Seconds, Math.Round(Convert.ToDecimal(ts.Milliseconds),2));
ClockTextBlock.Text = currentTime;
I've tried with Math.Round and nothing happened. The result is still anywhere from 1-3 digit, like this:
01:12:7
01:12:77
01:12:777
I want format to always be like
01:12:07
01:12:77

You need:
String.Format(#"Time : {0:mm\:ss\.ff}", ts)
Where "ts" is your TimeSpan object. You can also always extend this to include hours etc. The fff stuff is the number of significant digits of the second fractions

You can use a custom TimeSpan format string for that (here we're only displaying the first two digits of the milliseconds with ff, which represent the hundredths):
ClockTextBlock.Text = ts.ToString("mm\\:ss\\:ff");

You could set a DateTime type timezone and plus with Timespan span.
You would get a datetime and format it!
DateTime timezone = new DateTime(1, 1, 1);
TimeSpan span = stopWatch.Elapsed;
ClockTextBlock.Text=(timezone + span).ToString("mm:ss:ff");

Just put the format in toString and it simply will show you the desired format :)
Stopwatch s2 = new Stopwatch();
s2.Start();
Console.WriteLine(s2.Elapsed.ToString(#"hh\:mm\:ss"));

Since a millisecond is 1/1000 of a second, all you need to do is divide the milliseconds by 10 to get 100's of a second. If you are concerned about rounding, then just do it manually before the division.
int hundredths = (int)Math.Round((double)ts.Milliseconds / 10);
currentTime = String.Format("{0}:{1}:{2}", ts.Minutes.ToString(D2), ts.Seconds.ToString(D2), hundredths.ToString(D2);
ClockTextBlock.Text = currentTime;

How to format user input into time

I am writing a simple class in C# that all it does is print three float variables to a DOS console (hour, minutes, seconds). The output is something like this: Hour = 3, Minutes = 15, Seconds = 0. But I want to know how would I go about in formatting it to show 3:15:00 rather than Hour = 3, Minutes = 15, Seconds = 0
This is the method I created that prints out the info:
/// <summary>
/// Prints the time to the console
/// </summary>
public void PrintTime()
{
Console.WriteLine(pHour.ToString() + ":" + pMinutes.ToString() + ":" + Seconds.ToString());
}
Can someone help me figure out how to format this? I went online and found out about DateTime but it requires the date as well and I don't need to add that for this homework. Many thanks in advance!

You can use the string format that Console.WriteLine provides:
Console.WriteLine("{0}:{1:00}:{2:00}", pHour, pMinutes, Seconds);

A little bit out of context. One more method is to use DateTime class to output the string
DateTime.Now.ToString("yyyy MM dd HH:mm:ss.fff tt", [System.Globalization.CultureInfo]::GetCultureInfo("en-US"));
The advantage of this method is easy insertion of separators in Date. Disadvantage is you cant insert your normal text inside the format string.

You could use a DateTime object to represent your Time and just disregard the Date part. Or you could use a TimeSpan object to accomplish a similar feat.
Or, just disregard both entirely and print out your input values as is:
int hours = 5;
int minutes = 55;
int seconds = 7;
DateTime dt = new DateTime(2014, 1, 1, hours, minutes, seconds);
TimeSpan ts = new TimeSpan(hours, minutes, seconds);
Console.WriteLine("{0:00}:{1:00}:{2:00}", dt.Hour, dt.Minute, dt.Second);
Console.WriteLine("{0:00}:{1:00}:{2:00}", ts.Hours, ts.Minutes, ts.Seconds); // This is actually not needed for using a TimeSpan, see next line.
Console.WriteLine(ts);
Console.WriteLine("{0:00}:{1:00}:{2:00}", hours, minutes, seconds);
In action
https://dotnetfiddle.net/6lUwnR
Note that weird stuff will happen if you pass in out of range values in some cases, so make sure to validate your input! :)

How do I format a timespan to show me total hours?

I want to save the user's hours worked in a database varchar column, but by default, the formatted value includes days if the number of hours is more than 24. I just want the total number of hours.
For example: if a user works 10:00:00 hours today, then 13:00:00 hours tomorrow, and 3:30:00 hours the day after tomorrow then the formatted total I want is 26:30:00. Instead, I am seeing 1.2:30:00.
How can I get the formatting I want?
Also, when I save the value 40:00:00 in the database manually, and try to read it into a TimeSpan later, I get a bug.
How can I save the hours in the database the way I want, and still be able to read it back into a TimeSpan later?

You could do something like:
TimeSpan time = ...;
string timeForDisplay = (int)time.TotalHours + time.ToString(#"\:mm\:ss");

Try TimeSpan.TotalHours
String timeStamp = "40:00:00";
var segments = timeStamp.Split(':');
TimeSpan t = new TimeSpan(0, Convert.ToInt32(segments[0]),
Convert.ToInt32(segments[1]), Convert.ToInt32(segments[2]));
string time = string.Format("{0}:{1}:{2}",
((int) t.TotalHours), t.Minutes, t.Seconds);

How do I read a time value and then insert it into a TimeSpan variable

How do I read a time value and then insert it into a TimeSpan variables?

If I understand you correctly you're trying to get some user input in the form of "08:00" and want to store the time in a timespan variable?
So.. something like this?
string input = "08:00";
DateTime time;
if (!DateTime.TryParse(input, out time))
{
// invalid input
return;
}
TimeSpan timeSpan = new TimeSpan(time.Hour, time.Minute, time.Second);

From MSDN: A TimeSpan object represents a time interval, or duration of time, measured as a positive or negative number of days, hours, minutes, seconds, and fractions of a second. The largest unit of time used to measure duration is a day.
Here's how you can initialize it to CurrentTime (in ticks):
TimeSpan ts = new TimeSpan(DateTime.Now.Ticks);

TimeSpan span = new TimeSpan(days,hours,minutes,seconds,milliseonds);
Or, if you mean DateTime:
DateTime time = new DateTime(year,month,day,minutes,seconds,milliseconds);
Where all of the parameters are ints.

Perhaps using:
var span = new TimeSpan(hours, minutes, seconds);
If you mean adding two timespans together use:
var newSpan = span.Add(new TimeSpan(hours, minutes, seconds));
For more information see msdn.

You can't change the properties of a TimeSpan. You need to create a new instance and pass the new values there.