Private Structure cicnt
        Public CustomerID As String
        Public Count As Integer
        Public Sub New(ByVal ci As String, ByVal cnt As Integer)
            CustomerID = ci
            Count = cnt
        End Sub
    End Structure
 
   Private cicnts As New List(Of cicnt)

    Private Sub ...
        Dim dv As New DataView(mydataTable)
        dv.Sort = "CustomerID" ' Feld zu zählen
 
        Dim lci As String = dv(0)("CustomerID").ToString()
        Dim cnt As Integer = 0
        For Each drv As DataRowView In dv
            If drv("CustomerID").ToString() <> lci Then
                cicnts.Add(New cicnt(lci, cnt))
                lci = drv("CustomerID").ToString()
                cnt = 1
            Else
                cnt += 1
            End If
        Next
        cicnts.Add(New cicnt(lci, cnt))
    End Sub

________
Alle Angaben ohne Gewähr. Keine Haftung für Vorschläge, Tipps oder sonstige Hilfe, falls es schiefgeht, nur Zeit verschwendet oder man sonst nicht zufrieden ist