How do I compare the items of two listboxes?

[Me.User]

I have two listboxes (1: Primary, 2:Secondary). These listboxes contain numbers. The Primary Listbox contains 7 numbers, and the Secondary Listbox contains 6 numbers.



I want to compare the values of the Primary Listbox to those of the Secondary. This comparison should yield three results:

Result #1: X number of values were found to be common.



Result#2: All numbers matched.



Result#3: No matches found.



This is what I have so far:

If lstPrimaryNumbers.Items.Count = 0 Or lstSecondaryNumbers.Items.Count = 0 Then
            MessageBox.Show("There is nothing to compare.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End If


        Dim r = lstPrimaryNumbers.Items.Cast(Of String).Where(Function(x) lstSecondaryNumbers.Items.Contains(x))
        MessageBox.Show(String.Join(",", r) & " matched")

Note: I`m only dealing with integer values in the two listboxes.