Dim _ribbon As Ribbon

  Private Sub ButtonLoadRibbon_Click(sender As Object, e As EventArgs) Handles ButtonLoadRibbon.Click
    _ribbon = New Ribbon
    _ribbon.ResourceName = "RibbonTest.RibbonMarkup.ribbon"
    _ribbon.Dock = DockStyle.Top
    Me.Controls.Add(_ribbon)
  End Sub

  Private Sub ButtonUnloadRibbon_Click(sender As Object, e As EventArgs) Handles ButtonUnloadRibbon.Click
    _ribbon.Framework.Destroy()
    Me.Controls.Remove(_ribbon)
  End Sub

  Public Declare Function SetMenu Lib "user32.dll" (ByVal hwnd As IntPtr, ByVal hMenu As IntPtr) As Boolean

  Private Sub ButtonUnloadRibbon_Click(sender As Object, e As EventArgs) Handles ButtonUnloadRibbon.Click
    _ribbon.Framework.Destroy()
    Me.Controls.Remove(_ribbon)
    SetMenu(Me.Handle, MainMenu1.Handle)
  End Sub

  <StructLayout(LayoutKind.Sequential)>
  Public Structure RECT
    Dim Left As Integer
    Dim Top As Integer
    Dim Right As Integer
    Dim Bottom As Integer
  End Structure

  <StructLayout(LayoutKind.Sequential)>
  Public Structure WINDOWPOS
    Dim hwnd As IntPtr
    Dim hWndInsertAfter As IntPtr
    Dim x As Integer
    Dim y As Integer
    Dim cx As Integer
    Dim cy As Integer
    Dim Flags As UInteger
  End Structure

  <StructLayout(LayoutKind.Sequential)>
  Public Structure NCCALCSIZE_PARAMS
    Dim rgrc0 As RECT
    Dim rgrc1 As RECT
    Dim rgrc2 As RECT
    Dim lppos As WINDOWPOS
  End Structure

  Dim h_delta As Integer = 0
  Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
    'Debug.WriteLine(m.ToString())
    Dim csp As NCCALCSIZE_PARAMS

    Select Case m.Msg
      Case WM_NCCALCSIZE
        If m.WParam = IntPtr.Zero Then
        Else
          If _ribbon Is Nothing Then
            csp = CType(Marshal.PtrToStructure(m.LParam, GetType(NCCALCSIZE_PARAMS)), NCCALCSIZE_PARAMS)
            csp.rgrc0.Top = csp.rgrc0.Top + h_delta
            Marshal.StructureToPtr(csp, m.LParam, False)
            m.Result = IntPtr.Zero
          End If
        End If
        Debug.WriteLine(m.ToString())
    End Select


    ' Forward message to base WndProc.
    MyBase.WndProc(m)
  End Sub

  Dim _ribbon As Ribbon

  Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
  End Sub

  Private Sub ButtonUnloadRibbon_Click(sender As Object, e As EventArgs) Handles ButtonUnloadRibbon.Click
    Me.Controls.Remove(_ribbon)
    _ribbon.Framework.Destroy()
    _ribbon = Nothing
    SetMenu(Me.Handle, Me.MainMenu1.Handle)
  End Sub

  Private Sub ButtonLoadRibbon_Click(sender As Object, e As EventArgs) Handles ButtonLoadRibbon.Click
    Dim h_init As Integer = Me.ClientSize.Height
    _ribbon = New Ribbon
    _ribbon.ResourceName = "RibbonTest.RibbonMarkup.ribbon"
    _ribbon.Dock = DockStyle.Top
    _ribbon.TabStop = False
    Me.Controls.Add(_ribbon)
    If h_delta = 0 Then h_delta = Me.ClientSize.Height - h_init
    Debug.Print(h_delta)
  End Sub