[RESOLVED] How to improve this code?

Hi!

I have written a small method that keeps track of a pivot control containing months from jan-dec. The pivot can scroll both ways and I have to keep track of which way the scrolling occurs, and either reduce or increase the selecteddatetime by one month.

Here is the code so far

Code:

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Private Sub CalculateSelectedDate(lastSelected As Integer, selectedPivotIndex As Integer)
        Dim diff = lastSelected - selectedPivotIndex

        ' From feb-mar
        If diff < 0 AndAlso Math.Abs(diff) = 1 Then
                SelectedDate = SelectedDate.AddMonths(1)
        ' From mar-feb
        ElseIf diff > 0 AndAlso Math.Abs(diff) = 1 Then
                SelectedDate = SelectedDate.AddMonths(-1)

        ' From dec to jan
        ElseIf diff < 0 AndAlso Math.Abs(diff) > 1 Then
                SelectedDate = SelectedDate.AddMonths(-1)

        ' From jan to dec
        ElseIf diff > 0 AndAlso Math.Abs(diff) > 1 Then
                SelectedDate = SelectedDate.AddMonths(1)
        End If
End Sub

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I am almost certain this code can be written in a better way, and I am interested in knowing your opinions on how to refactor it?

What I check is

* which way the navigation is going by comparing last index and current index

* and two special cases for navigating between years

/Henrik

Why do you think it needs improving? What calculation do you think could be extracted out and performed only once?

If diff < 0 AndAlso Math.Abs(diff) = 1 Then 'That is the same as diff = -1
ElseIf diff > 0 AndAlso Math.Abs(diff) = 1 Then 'This is the same as 1
ElseIf diff < 0 AndAlso Math.Abs(diff) > 1 Then 'This is the same as <-1
ElseIf diff > 0 AndAlso Math.Abs(diff) > 1 Then 'And finally the same as >1

Code:

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Dim intMonths As Integer = 0
        Select Case lastSelected - selectedPivotIndex
            Case Is < -1, 1
                intMonths = -1
            Case Is > 1, -1
                intMonths = 1
        End Select
        SelectedDate = SelectedDate.AddMonths(intMonths)

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Numerous ways to do that.

Thanks, I figured the code was overly complex!

/H