Frequency distribution generator

Fd.vb

Public Class Form1

    Class Pair
        Public first As String
        Public second As String
    End Class

    Function generateFrequency() As ArrayList

        If (dataList.Items.Count > 0 And txtbClassSize.Text.Length > 0) Then


            Dim min As Integer = dataList.Items.Item(0)
            Dim max As Integer = dataList.Items.Item(0)

            For digitCount = 0 To dataList.Items.Count
                Try
                    If (dataList.Items.Item(digitCount) < min) Then
                        min = dataList.Items.Item(digitCount)
                    End If
                Catch e As ArgumentOutOfRangeException

                End Try
            Next


            For digitCount = 0 To dataList.Items.Count
                Try
                    If (dataList.Items.Item(digitCount) > max) Then
                        max = dataList.Items.Item(digitCount)
                    End If
                Catch e As ArgumentOutOfRangeException

                End Try
            Next

            MsgBox(min & " min")
            MsgBox(max & " max")

            Dim range As Integer = max - min
            Dim noc As Integer = (range / CInt(txtbClassSize.Text)) + 1

            Dim currentInterval As Integer

            Dim classInterval As New ArrayList
            Dim frequency As New ArrayList

            For interval = 0 To noc - 1

                currentInterval = max - CInt(txtbClassSize.Text) + 1

                Dim pair As New Pair

                pair.first = currentInterval
                pair.second = max

                MsgBox(pair.first & " " & pair.second)

                classInterval.Add(pair)


                max = currentInterval - 1

            Next

            Dim count As Integer = 0

            MsgBox("datalist " & dataList.Items.Count)

            For pairCount = 0 To classInterval.Count - 1
                Dim pair As Pair = classInterval.Item(pairCount)


                For digitCount = 0 To dataList.Items.Count
                    
                    Try
                        If (CInt(dataList.Items.Item(digitCount)) >= pair.first And
                            CInt(dataList.Items.Item(digitCount)) <= pair.second) Then
                            count += 1
                        End If
                    Catch e As ArgumentOutOfRangeException
                    End Try
                Next

                frequency.Add(count)
                count = 0

            Next

            For insertCount = 0 To frequency.Count - 1
                Dim getPair As Pair = classInterval.Item(insertCount)

                dataTable.Rows.Add(New String() {getPair.first & " - " & getPair.second, frequency.Item(insertCount)})
            Next



        Else
            If (dataList.Items.Count <= 0 And txtbClassSize.Text.Length <= 0) Then
                MsgBox("add some digits and class size")
            ElseIf (dataList.Items.Count <= 0) Then
                MsgBox("add some digits")
            Else
                MsgBox("need to have a class size")
            End If
        End If


    End Function

    Private Sub btnEnter_Click(sender As Object, e As EventArgs) Handles btnEnter.Click

        If (IsNumeric(txtbDigit.Text)) Then
            dataList.Items.Add("      " & txtbDigit.Text)
            txtbDigit.Clear()
        Else
            If (txtbDigit.Text.Length <= 0) Then
                MsgBox("empty", MsgBoxStyle.Exclamation, "cant enter")
            Else
                MsgBox("enter a digit", MsgBoxStyle.Exclamation, "enter some digits")
            End If

        End If

    End Sub

    Private Sub btnReset_Click(sender As Object, e As EventArgs) Handles btnReset.Click
        txtbDigit.Text = ""
        txtbClassSize.Text = ""

        dataList.Items.Clear()
        dataTable.Rows.Clear()

    End Sub

    Private Sub btnStart_Click(sender As Object, e As EventArgs) Handles btnStart.Click
        dataTable.Rows.Clear()
        txtbClassSize.Text = ""

        generateFrequency()
    End Sub

    Private Sub txtbDigit_Enter(sender As Object, e As EventArgs)
        If (IsNumeric(txtbDigit.Text)) Then
            dataList.Items.Add("      " & txtbDigit.Text)
            txtbDigit.Clear()
        Else
            If (txtbDigit.Text.Length <= 0) Then
                MsgBox("empty", MsgBoxStyle.Exclamation, "cant enter")
            Else
                MsgBox("enter a digit", MsgBoxStyle.Exclamation, "enter some digits")
            End If

        End If

    End Sub

    Private Sub txtbDigit_KeyUp(sender As Object, e As KeyEventArgs) Handles txtbDigit.KeyUp
        If (e.KeyValue = Keys.Enter) Then
            If (IsNumeric(txtbDigit.Text)) Then
                dataList.Items.Add("      " & txtbDigit.Text)
                txtbDigit.Clear()
            Else
                If (txtbDigit.Text.Length <= 0) Then
                    MsgBox("empty", MsgBoxStyle.Exclamation, "cant enter")
                Else
                    MsgBox("enter a digit", MsgBoxStyle.Exclamation, "enter some digits")
                End If

            End If
        End If
    End Sub
End Class