Public Class Form1
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) _
      Handles MyBase.Load
        ComboBox1.Items.Add("Zeile 1")
    End Sub
    'Delete-Taste gedrückt
    Private Sub ComboBox1_KeyDown(sender As System.Object, e As _
      System.Windows.Forms.KeyEventArgs) Handles ComboBox1.KeyDown
        If e.KeyCode = Keys.Delete Then
            If ComboBox1.DroppedDown = True Then
                If ComboBox1.SelectedIndex > -1 Then
                    ComboBox1.Items.RemoveAt(ComboBox1.SelectedIndex)
                End If
            End If
        End If
    End Sub
    'Beenden 
    Private Sub btnBeenden_Click(sender As System.Object, e As _
      System.EventArgs) Handles btnBeenden.Click
        Me.Close()
    End Sub
End Class