Private Sub SetClipRectangle(ByVal e As PaintEventArgs)

    ' Create rectangle for clipping region.
    Dim clipRect As New Rectangle(0, 0, 100, 100)

    ' Set clipping region of graphics to rectangle.
    e.Graphics.SetClip(clipRect)

    ' Fill rectangle to demonstrate clip region.
    e.Graphics.FillRectangle(New SolidBrush(Color.Black), 0, 0, _
    500, 300)
End Sub

private void SetClipRectangle(PaintEventArgs e)
{

    // Create rectangle for clipping region.
    Rectangle clipRect = new Rectangle(0, 0, 100, 100);

    // Set clipping region of graphics to rectangle.
    e.Graphics.SetClip(clipRect);

    // Fill rectangle to demonstrate clip region.
    e.Graphics.FillRectangle(new SolidBrush(Color.Black), 0, 0, 500, 300);
}