Public Class Form1
 
    Dim ApPath As String
    Dim MousePoint As Point
    Dim Rect As Rectangle
    Dim Rectold As Rectangle
    Dim b As New SolidBrush(Color.Pink)
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
 
        'Hintergrundbild Laden
        ApPath = Application.StartupPath
        Dim Bild As String = ApPath & "\Bilder\background.jpg"
        PictureBox1.Size = Me.Size
        PictureBox1.BackgroundImage = New Bitmap(ApPath & _
          "\Bilder\background.jpg")
 
        'Variablen Test
        MousePoint.X = 0
        MousePoint.Y = 0
        Rectold.X = 0
        Rectold.Y = 0
        Rectold.Width = 50
        Rectold.Height = 50
 
    End Sub
 
    'Größe Hintergrund anpassen
    Private Sub Form1_Resize(ByVal sender As Object, ByVal e As _
      System.EventArgs) Handles Me.Resize
        PictureBox1.Size = Me.Size
    End Sub
 
    Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
 
        'Rechteck in Kreisgröße zeichnen (Mittelpunt = Punkt der Maus)
        Rect.X = e.X - 25
        Rect.Y = e.Y - 25
        Rect.Width = 50
        Rect.Height = 50
 
        'Punkt der Maus Soll Mitte des Kreises werden
        MousePoint.X = e.X - 25
        MousePoint.Y = e.Y - 25
 
        'Bildausschnitte neu Zeichnen (alte Position der Maus und neue)
        PictureBox1.Invalidate(Rectold)
        PictureBox1.Invalidate(Rect)
 
        Rectold = Rect
    End Sub
 
    Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
 
        'Punkt zeichnen
        e.Graphics.FillEllipse(b, MousePoint.X, MousePoint.Y, 50, 50)
 
    End Sub
 
End Class