Comparing .Net Version instance using CompareTo does not work as expected.

Question

The Version class in .Net does not implement the CompareTo interface as I would expect, it seems to handle the compare alphanumerically instead of comparing the four numbers. Maybe not a bug, but a 'feature'.

Can anyone shine a light on why the compare (and also the standard <, = and > operators) do not work as I would expect below?

    Dim MainVersion As New Version("1.1.3251.4029")
    Dim Ver_Low As New Version("1.1")
    Dim Ver_Same As New Version("1.1.3251.4029")
    Dim Ver_High As New Version("1.1.5.0")

    ' CompareTo here yields 1 which is expected as MainVersion is greater than Ver_Low.
    MessageBox.Show(String.Format("{0}.CompareTo({1}) = {2}", MainVersion.ToString(), Ver_Low.ToString(), MainVersion.CompareTo(Ver_Low).ToString()))

    ' CompareTo here yields 0 which is expected as MainVersion and Ver_Same are the same.
    MessageBox.Show(String.Format("{0}.CompareTo({1}) = {2}", MainVersion.ToString(), Ver_Same.ToString(), MainVersion.CompareTo(Ver_Same).ToString()))

    ' **** Issue here **** CompareTo here yields 1 which is NOT expected as MainVersion is less than Ver_High.
    MessageBox.Show(String.Format("{0}.CompareTo({1}) = {2}", MainVersion.ToString(), Ver_High.ToString(), MainVersion.CompareTo(Ver_High).ToString()))

I know people have done their own manual workarounds for this, I'd like to know if this is by design or it should work and I might be doing something dumb.

Thanks in advance

Ryan

Update: I was doing something subtly dumb and treating them in the same was as IP addresses. For example; 1.1.3023.5364 is greater than 1.1.5 but 1.1.3023.5364 is < than 1.1.5000.

Answer 1

No, it's comparing the four parts, treating each as a number. Which is the bigger number: 5 or 3251? Surely it's 3251. Therefore version 1.1.3251.* is "newer" (i.e. greater) than 1.1.5.*.

If you've got 1.1.3251 coming before 1.1.5, then you're effectively using a single number (the "build" part) as a sequence of digits. That's a mistake.