Public Class Form1
    Private Pb As New PictureBox With {.Dock = DockStyle.Fill, .Image = _
      SystemIcons.Error.ToBitmap, .SizeMode = PictureBoxSizeMode.Zoom, .Parent _
      = Me}
    Private Gb1 As New MyGroupBox With {.Bounds = New Rectangle(10, 10, 100, _
    230), .BackColor = Color.Transparent}
    Private Gb2 As New GroupBox With {.Bounds = New Rectangle(170, 10, 100, _
    230), .BackColor = Color.Transparent}
    Private WithEvents T As New Timer With {.Interval = 20, .Enabled = True}
 
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) _
      Handles MyBase.Load
        Gb1.Parent = Pb
        Gb2.Parent = Pb
    End Sub
 
    Private Sub T_Tick(sender As Object, e As System.EventArgs) Handles T.Tick
        Pb.Invalidate()
    End Sub
End Class
 
Public Class MyGroupBox
    Inherits GroupBox
    Sub New()
        Me.DoubleBuffered = True
    End Sub
End Class