Protected Overrides Sub OnPaint( _ 
                ByVal e As System.Windows.Forms.PaintEventArgs) 
        MyBase.OnPaint(e) 

        Dim rect As Rectangle = ClientRectangle 

        If designmode Then 
            ControlPaint.DrawBorder(e.Graphics, rect, Color.Gray, ButtonBorderStyle.Dashed) 
            Me.AutoScroll = True 
        Else 
            Me.AutoScroll = False 
        End If 
    End Sub 

Public Class MyPanel
Inherits Panel
Private Sub MyPanel_ControlAdded(ByVal sender As Object, ByVal e As System.Windows.Forms.ControlEventArgs) Handles Me.ControlAdded
Me.AutoScroll = DesignMode
End Sub
End Class