VB time input, a better way to do it?

Question

Hello Stack overflow,

Working on a handy program for my boss at work as a summer project in between semesters both to make life easier for her, and to practice and improve my skills. Intent is to allow her to quickly and easily calculate the hours and minutes the person worked. The form itself has a series of text boxes for the Clock in and Clock out time for each day that week. Currently it attempts to convert the txtbox text into a Date variable, then .Subtract()'s the start from the end and stores it in a rolling total variable which is displayed at the bottom of the form. I can't help but think there is a better way of going about doing this, and I'm absolutely certain that having the below block of code 21 times (7 days, 3 shifts) is inefficient.

    Dim StartTime As Date
    Dim EndTime As Date
    Dim Worked As System.TimeSpan
    Dim WorkedTotal As System.TimeSpan
    If chkFirst.Checked = True Then
            StartTime = CDate(txtMonStart.Text)
            EndTime = CDate(txtMonEnd.Text)
            EndTime = EndTime.AddHours(12)
            Worked = EndTime.Subtract(StartTime)
            lblMonWork.Text = Worked.ToString()
            WorkedTotal += Worked

Currently it works, mostly. The user has to enter the ":" in the time input, and if the total exceeds 24 hours, it displays a day column (40 hour 12 min work week displays as 1.16:12). I'd like to eliminate both of these unplanned features and allow for my input validation to take place when the focus changes to another box. A changing bgcolor would indicate an invalid input.

Any bright ideas?

Answer 1

Instead of using TextBox for the time input, use DateTimePicker, just change the Format property to Time.

Handle the Validating event of the DateTimePicker and if it's invalid just set e.Cancel = False, that way they can't save changes unless it's valid. Or if you want them to be able to leave the DateTimePicker and just change the colour, just handle the ValueChanged event instead.

Regarding your code sample, I haven't really looked at the logic of it, but instead of having the same code 21 times, just move the code into a separate function and then call that function with the start and end times as parameters and it can return the workedtime as it's return value.

I'm not sure what your UI looks like but if you're repeating the start time and end time input control multiple times as well it might be worth looking at creating your own usercontrol that can contain one each of the start and end time controls, and then you could have the validation be inside that user control so you don't have to have lots of event handlers etc.