Time Check Function

[geo039]

I tried to write a simple application that takes user input by text and time selected by date time picker. It displays the appt description in one
list box and the time in another list box. I wrote a simple function
that checks the times for duplicates. I wanted to check for a duplicate
before it writes to the listbox by returning a boolean (true/false)
value. I only need to check hours and minutes not date or seconds. The following is what I have, it's not recognizing the duplicates, am I confused in how the function reads? Any suggestions?

If (txtAppointment.Text = "") Then
            'invalid input, alert user
            MessageBox.Show(Text:="You Must Enter an Appointment Description", _
                caption:="Input error - Add Appointment")
            'select the invalid input
            txtAppointment.SelectAll()
            txtAppointment.Focus()
 
        Else
 
            Dim Time As Boolean
 
            Time = TimeTaken(Me.dtmTime.Value.ToShortDateString)
 
            If Time Then
                MessageBox.Show("You already have an appointment at this time")
            Else
 
            'display appointment in Listbox
                lstApptResults.Items.Add(txtAppointment.Text)
                txtAppointment.Clear() 'clear appointment from TextBox
                txtAppointment.Focus() 'transfer focus to TextBox
 
            'display appointment time in Listbox
                lstTimeResults.Items.Add(Me.dtmTime.Value.ToShortTimeString)
 
            End If
        End If
    End Sub 'btnAddAppt_Click
    'function to check if an appointment time already exists in listbox
    Public Function TimeTaken(ByVal ApptTime As DateTime) As Boolean
 
        Dim DuplicateTime As Boolean = False
 
        'loop that checks listed times for duplicates
        For Each strItem As String In lstTimeResults.Items
            If strItem = ApptTime Then
                DuplicateTime = True
 
                Exit For
            End If
        Next
 
        Return DuplicateTime
    End Function 'TimeTaken

[Lok]

If (txtAppointment.Text = "") Then
            'invalid input, alert user
            MessageBox.Show(Text:="You Must Enter an Appointment Description", _
                caption:="Input error - Add Appointment")
            'select the invalid input
            txtAppointment.SelectAll()
            txtAppointment.Focus()
 
        Else
 
            Dim Time As Boolean
 
            Time = TimeTaken(Me.dtmTime.Value.ToShortDateString)
 
            If Time Then
                MessageBox.Show("You already have an appointment at this time")
            Else
 
            'display appointment in Listbox
                lstApptResults.Items.Add(txtAppointment.Text)
                txtAppointment.Clear() 'clear appointment from TextBox
                txtAppointment.Focus() 'transfer focus to TextBox
 
            'display appointment time in Listbox
                lstTimeResults.Items.Add(Me.dtmTime.Value.ToShortTimeString)
 
            End If
        End If
    End Sub 'btnAddAppt_Click
    'function to check if an appointment time already exists in listbox
    Public Function TimeTaken(ByVal ApptTime As DateTime) As Boolean
 
        Dim DuplicateTime As Boolean = False
 
        'loop that checks listed times for duplicates
        For Each strItem As String In lstTimeResults.Items
            If strItem = ApptTime Then
                DuplicateTime = True
 
                Exit For
            End If
        Next
 
        Return DuplicateTime
    End Function 'TimeTaken

Try to investigate whether the parameter value that you sent to the TimeTaken function is what you expected (eg. put a MsgBox or something to inspect the value).

I don't have chance to try it, but so far from what I'm read your code, that your listbox items are string. Your time-input is also a string (gained from .ToShortTimeString). But why your TimeTaken parameter type is a DateTime ?

When the program run, the original time entered by the user will be convert to a string using .ToShortTimeString, the when passed to the TimeTaken function, it will converted back to DateTime. Then when compared to the listbox items, it will converted again to a string (using DateTime default format).

Don't know, maybe it's the root of the problem. Please check.

regards,
Lok

[geo039]

I think the conversion is where I am confused. The user writes their appt in a text box and selects a time from a datetimepicker. The input from text goes to one list box and the time to another. I want to check against the times only but somewhere along the lines it's not checking the time as a time. The functionality works the function just isn't picking up the time as a format needing to check for duplicates for some reason.

[Lok]

Ok, then make it in the same format then, avoid any conversion. So you must be firm, decide one, keep it as a string, or as a DateTime.

As a string, after user pick the DateTime using DatePicker, convert it to string. Put inside listbox (also as a string), then when you want to compare, compare it also string to string.

As a DateTime, after user pick the DateTime using DatePicker, convert it to string (why? it's the easiest way to populate listbox), then when you want to compare, get the item from the listbox, convert it back to DateTime, then compare it DateTime to DateTime.

If you want to put more effort, create a custom ListBoxItem class, overriding its ToString() method (a string value with specific date/time format that you required). So you can still keep the original DateTime value to be use for comparison.

Regards,

Lok

[geo039]

Got the simple problem to work. Sometimes after all is said and done the solution ends up being something so simple. After staring at something for hours it all just starts to go to mush.

Thanks Again