How do I make a selection rectangle visible over a tablelayoutpanel

The selection rectangle can be seen when the visible property of the tablelayoutpanel is set to false, but when it is set to true, it can't be seen.

Eventually I will populate the tablelayoutpanel with controls and the selection grid needs to work with these as well.

The tablelayoutpanel fills the whole form.
Public Class TableLayoutForm
    Dim isDrag As Boolean = False
    Dim theRectangle As New Rectangle(New Point(0, 0), New Size(0, 0))
    Dim startPoint As Point
    Dim endpoint As Point

    Private Sub Form1_MouseDown(ByVal sender As Object, ByVal e As  _
        System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseDown

        ' Set the isDrag variable to true and get the starting point 
        ' by using the PointToScreen method to convert form coordinates to
        ' screen coordinates.
        If (e.Button = MouseButtons.Left) Then
            isDrag = True
        End If

        Dim control As Control = CType(sender, Control)

        ' Calculate the startPoint by using the PointToScreen 
        ' method.
        startPoint = control.PointToScreen(New Point(e.X, e.Y))
    End Sub

    Private Sub Form1_MouseMove(ByVal sender As Object, ByVal e As  _
    System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseMove

        ' If the mouse is being dragged, undraw and redraw the rectangle
        ' as the mouse moves.
        If (isDrag) Then

            ' Hide the previous rectangle by calling the DrawReversibleFrame 
            ' method with the same parameters.
            ControlPaint.DrawReversibleFrame(theRectangle, Me.BackColor, _

            ' Calculate the endpoint and dimensions for the new rectangle, 
            ' again using the PointToScreen method.
            endpoint = CType(sender, Control).PointToScreen(New Point(e.X, e.Y))
            Dim width As Integer = endPoint.X - startPoint.X
            Dim height As Integer = endPoint.Y - startPoint.Y
            theRectangle = New Rectangle(startPoint.X, startPoint.Y, _
                width, height)

            ' Draw the new rectangle by calling DrawReversibleFrame again.  
            ControlPaint.DrawReversibleFrame(theRectangle, Me.BackColor, _
        End If
    End Sub

    Private Sub Form1_MouseUp(ByVal sender As Object, ByVal e As  _
    System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseUp

        ' If the MouseUp event occurs, the user is not dragging.
        isDrag = False

        ' Draw the rectangle to be evaluated. Set a dashed frame style 
        ' using the FrameStyle enumeration.
        ControlPaint.DrawReversibleFrame(theRectangle, Me.BackColor, _

        ' Find out which controls intersect the rectangle and change their color.
        ' The method uses the RectangleToScreen method to convert the 
        ' Control's client coordinates to screen coordinates.
        Dim i As Integer
        Dim controlRectangle As Rectangle
        For i = 0 To Controls.Count - 1
            controlRectangle = Controls(i).RectangleToScreen _
            If controlRectangle.IntersectsWith(theRectangle) Then
                Controls(i).BackColor = Color.BurlyWood
            End If
        ' Reset the rectangle.
        theRectangle = New Rectangle(0, 0, 0, 0)
    End Sub

    Public Sub New()

        ' This call is required by the Windows Form Designer.

        ' Add any initialization after the InitializeComponent() call.
    End Sub
End Class

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Who is Participating?
Mike TomlinsonMiddle School Assistant TeacherCommented:
It works when the TableLayoutPanel is not visible because the events are being trapped by the Form itself.  With the TableLayoutPanel taking up the whole form, the events will now be fired in the TableLayoutPanel instead.

So you need to wire up the MouseDown(), MouseMove(), and MouseUp() events for the TableLayoutPanel in a similar fashion to what you've already done with the form.
alukesAuthor Commented:
After you explained it, it makes perfect sense. I should have thought of that earleir.

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