Die Bezeichnungen am Dreieck

Public Class Form1


    Private Sub Form1_Load(sender As Object, e As EventArgs) _
        Handles Me.Click ' wenn Form1 geklickt, inhalt löschen
        Invalidate()        'Löschen, ungültig


    End Sub


    Private Sub Form1_MouseMove(sender As Object, _
                                e As System.Windows.Forms.MouseEventArgs) _
                            Handles Me.MouseMove


        Dim ptA As New Size(-15, -10)
        Dim ptB As New Size(-10, -20)
        Dim ptC As New Size(-10, -10)
        Dim ptkla As New Size(10, 10)
        Dim ptklb As New Size(10, 10)
        Dim ptklc As New Size(10, 10)


        Dim g As Graphics = CreateGraphics()
        g.TextRenderingHint = Drawing.Text.TextRenderingHint.SingleBitPerPixelGridFit


        Dim ptMitte As New PointF(CSng(ClientSize.Width / 2), _
                                  CSng(ClientSize.Height / 2))
        Static ptMouse As New PointF(e.X, e.Y)  'vorherrige Mausposition


        Dim pp As New Pen(BackColor)  ' Löschen mit BackColor 
        Dim bb As New SolidBrush(BackColor) 'Löschen
        Dim fn As New Font("Arial", 10)


        g.DrawLine(pp, ptMitte, ptMouse)
        g.DrawLine(pp, ptMouse, New PointF(ptMitte.X, ptMouse.Y))
        g.DrawLine(pp, ptMouse, New PointF(ptMouse.X, ptMitte.Y))


        Dim pointc = New PointF(ptMouse.X, ptMitte.X)


        ptMouse = New PointF(e.X, e.Y)        'aktuelle Mausposition
        Refresh()
        'Hypothenuse sichtbar zeichnen mit aktueller Mausposition
        pp.Color = Color.Red
        bb.Color = Color.Black
        g.DrawLine(pp, ptMitte, ptMouse)
        g.DrawLine(pp, ptMitte, New PointF(ptMouse.X, ptMitte.Y))               'Horizontal
        g.DrawLine(pp, ptMouse, New PointF(ptMouse.X, ptMitte.Y))               'Wagerecht


        g.DrawString("A", fn, bb, PointF.Add(ptMitte, ptA))
        g.DrawString("B", fn, bb, PointF.Add(ptMouse, ptB))
        g.DrawString("C", fn, bb, PointF.Add(pointc, ptC))


    End Sub


End Class