Dim bolRubberboxVisible As Boolean = False
    Dim bolRubberboxCancel As Boolean = False
    Dim pRubberBox As Point
    Dim sRubberBox As Size
 
    Private Sub PictureBox1_MouseDown(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
        bolRubberboxCancel = False
        pRubberBox = New Point(Control.MousePosition.X, Control.MousePosition.Y)
        sRubberBox = New Size(0, 0)
        ' Startrechteck zeichnen
        DrawRubberBox()
    End Sub
 
    Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
        If (e.Button <> MouseButtons.None) And (bolRubberboxCancel = False) Then
            ' bisheriges Rechteck löschen
            RemoveRubberBox()
            ' neues Rechteck zeichnen
            sRubberBox = New Size(Control.MousePosition.X - pRubberBox.X, _
              Control.MousePosition.Y - pRubberBox.Y)
            DrawRubberBox()
        End If
    End Sub
 
    Private Sub PictureBox1_MouseUp(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseUp
        If bolRubberboxCancel Then Exit Sub
        ' Rechteck löschen
        RemoveRubberBox()
    End Sub
 
    Private Sub DrawRubberBox()
        bolRubberboxVisible = True
        ControlPaint.DrawReversibleFrame(New Rectangle(pRubberBox, sRubberBox), _
          Color.White, FrameStyle.Dashed)
    End Sub
 
    Private Sub RemoveRubberBox()
        If bolRubberboxVisible = True Then ControlPaint.DrawReversibleFrame(New _
          Rectangle(pRubberBox, sRubberBox), Color.White, FrameStyle.Dashed)
        bolRubberboxVisible = False
    End Sub