Question

i keep running in this issue where it will jump out of the for statements that generate the table, I’ve been pouring over the code for a better part of three hours and i cannot find what is going wrong so i think i need another pair of eyes.


Shared Function DrawGrid() As TableLayoutPanel
Dim dayNames As New ArrayList
dayNames.Add(“Monday”)
dayNames.Add(“Tuesday”)
dayNames.Add(“Wednesday”)
dayNames.Add(“Thursday”)
dayNames.Add(“Friday”)
dayNames.Add(“Saturday”)
dayNames.Add(“Sunday”)
Dim hour As Integer = 8
Dim minute As Integer = 0
Dim timeType As String = “AM”
Dim dayLength As Integer = 12
Dim timetable As New TableLayoutPanel
timetable.CellBorderStyle = TableLayoutPanelCellBorderStyle.Inset

'Loops through days one at a time this creates the labels and adds them for reference by the user but is not needed for the timetable creation
For days As Integer = 0 To 7
    timetable.ColumnCount += 1
    timetable.RowCount += 1
    If days > 0 Then
        Dim NamePos As New TableLayoutPanelCellPosition(days, 0)
        Dim lblDay As New Label

        lblDay.Text = CStr(dayNames.Item(days))

        timetable.SetCellPosition(lblDay, NamePos)
        timetable.Controls.Add(lblDay)
    End If

    For time As Integer = 0 To dayLength
        Dim rowPos As New TableLayoutPanelCellPosition(days, time)
        Dim lblTime As New Label
        Dim timeString As String
        timetable.RowCount += 1
        If days = 0 Then
            minute += 6
            If minute = 6 Then
                minute = 0
                hour += 1

            End If
            If hour = 13 Then
                hour = 1
                timeType = "PM"
            End If
            timeString = "Time is " & hour & ":" & minute & "0 " & timeType
            lblTime.Text = timeString

            timetable.SetCellPosition(lblTime, rowPos)

            timetable.Controls.Add(lblTime)
            timetable.Visible = True

        End If


    Next
Next
timetable.GrowStyle = TableLayoutPanelGrowStyle.AddColumns
timetable.AutoSize = True
MessageBox.Show("Working")
Return timetable

End Function


Answer 1

Are you able to add a breakpoint to the For loop to see at what point error is being generated? If so check what the local variable values are just before it throws the exception.

An out of range exception can be because you are trying to access an array/collection item that doesn’t exist.

For instance myArray(4) has 5 items, if I try to access myArray(5) I will get an out of range exception, because the index starts at 0.