Private Sub btnListfill_Click(ByVal sender As System.Object, ByVal e As _
   System.EventArgs) Handles btnListfill.Click
 
        vA = CDbl(txtAwert.Text)
        vB = CDbl(txtBwert.Text)
        vC = CDbl(txtCwert.Text)
        vXstart = CDbl(txtXstart.Text)
        vXende = CDbl(txtXende.Text)
        vXschritt = CDbl(txtXschritte.Text)
 
        Dim vP, vQ As Double
 
        vPCount = vPCount + 1
 
        listGroup = vA & "x² + " & vB & "x + " & vC
        vP = vB / vA
        vQ = vC / vA
 
        vNull1 = -vP / 2 + Math.Sqrt(Math.Pow(vP / 2, 2) - vQ)
        vNull2 = -vP / 2 - Math.Sqrt(Math.Pow(vP / 2, 2) - vQ)
 
        Dim vX01, vX02 As String
        vX01 = vNull1.ToString.Substring(0, 4)
        vX02 = vNull2.ToString.Substring(0, 4)
 
 
        If vPCount = 1 Then
            listParabel.Items.Add(listGroup).SubItems.Add(vX01 & " & " & vX02)
            listParabel.Items.Item(vPCount - 1).ForeColor = vColor1
            Call parabellistfill()
        ElseIf vPCount = 2 Then
            listParabel.Items.Add(listGroup).SubItems.Add(vX01 & " & " & vX02)
            listParabel.Items.Item(vPCount - 1).ForeColor = vColor2
            Call parabellistfill()
        ElseIf vPCount = 3 Then
            listParabel.Items.Add(listGroup).SubItems.Add(vX01 & " & " & vX02)
            listParabel.Items.Item(vPCount - 1).ForeColor = vColor3
            Call parabellistfill()
        ElseIf vPCount = 4 Then
            listParabel.Items.Add(listGroup).SubItems.Add(vX01 & " & " & vX02)
            listParabel.Items.Item(vPCount - 1).ForeColor = vColor4
            Call parabellistfill()
        ElseIf vPCount = 5 Then
            listParabel.Items.Add(listGroup).SubItems.Add(vX01 & " & " & vX02)
            listParabel.Items.Item(vPCount - 1).ForeColor = vColor5
            Call parabellistfill()
        Else
            MessageBox.Show("Maximal 5 Parabeln!", "Halt!", _
              MessageBoxButtons.OK, MessageBoxIcon.Error)
        End If
 
 
 
 
    End Sub 'Liste auffüllen
    Public Sub parabellistfill()
        listGroups = New ListViewGroup(listGroup)
 
 
        listWerte.Groups.Add(listGroups)
 
        For vX As Integer = vXstart To vXende Step vXschritt
 
 
 
            vY = vA * vX * vX + vB * vX + vC
            listWerte.Items.Add(New ListViewItem(vX, listGroups)).SubItems.Add( _
              vY)
 
 
        Next
 
 
 
 
    End Sub
 
 
    Private Sub btnZeichnen_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles btnZeichnen.Click
        Form2.Show()
    End Sub
 
    Private Sub btnPardelall_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles btnPardelall.Click
        listParabel.Items.Clear()
        listParabel.Groups.Clear()
        listWerte.Items.Clear()
        listWerte.Groups.Clear()
        vPCount = 0
 
    End Sub
 
    Private Sub LinkLabel1_LinkClicked(ByVal sender As System.Object, ByVal e _
      As System.Windows.Forms.LinkLabelLinkClickedEventArgs) Handles _
      LinkLabel1.LinkClicked
        Form3.Show()
    End Sub
 
End Class