Private Sub Button2Click(sender As System.Object, e As System.EventArgs)
    Dim dt As System.Data.DataTable = New System.Data.DataTable
    dim dr As System.Data.DataRow 
    dt.Columns.Add("Vorname")
    dt.Columns.Add("Nachname")
    dr = dt.newrow
    dr("Vorname") = "Hans"
    dr("Nachname") = "Meier"
    dt.Rows.Add (dr)
 
    dr = dt.newrow
    dr("Vorname") = "Werner"
    dr("Nachname") = "Müller"
    dt.Rows.Add (dr)
 
    Me.comboBox.DataSource = dt
    Me.comboBox.ValueMember = "Vorname"
    Me.comboBox.DisplayMember = "Nachname"
End Sub
Private Sub ComboBoxSelectedIndexChanged(sender As System.Object, e As _
  System.EventArgs)
  Debug.WriteLine(me.comboBox.SelectedValue.ToString())
End Sub