How to hide an item from customization in WinForms MainFrameBarManager (Menu)?

this.mainFrameBarManager1.CustomizingItemChanged += new EventHandler(mainFrameBarManager1_CustomizingItemChanged);
this.mainFrameBarManager1.CustomizationBegin += new EventHandler(mainFrameBarManager1_CustomizationBegin);
this.mainFrameBarManager1.CustomizationDone += new EventHandler(mainFrameBarManager1_CustomizationDone);
void mainFrameBarManager1_CustomizationDone(object sender, EventArgs e)
{
   //throw new Exception("The method or operation is not implemented.");
   // Unhide the item.
   this.parentBarItem1.Visible = true;
   // Make the category visible again in the customization dialog.
   this.mainFrameBarManager1.CategoriesToIgnoreInCustDialog.Remove(this.parentBarItem1.CategoryIndex);
}
void mainFrameBarManager1_CustomizationBegin(object sender, EventArgs e)
{
   //throw new Exception("The method or operation is not implemented.");
   // Hide an item’s Category from appearing in the Customization Dialog.
   this.mainFrameBarManager1.CategoriesToIgnoreInCustDialog.Add(this.parentBarItem1.CategoryIndex);
   // Also hide the item itself.
   this.parentBarItem1.Visible = false;
}
void mainFrameBarManager1_CustomizingItemChanged(object sender, EventArgs e)
{
   //throw new Exception("The method or operation is not implemented.");
   // Prevent a particular item from being Customized via Alt + Click.
   if (this.mainFrameBarManager1.CustomizingItem == this.parentBarItem1)
   {
       this.mainFrameBarManager1.EndDragAndDropCustomizing();
   }
}

AddHandler MainFrameBarManager1.CustomizationBegin, AddressOf Customization_Begin
AddHandler MainFrameBarManager1.CustomizationDone, AddressOf Customization_Done
AddHandler MainFrameBarManager1.CustomizingItemChanged, AddressOf mainFrameBarManager1_CustomizingItemChanged
Private Sub mainFrameBarManager1_CustomizingItemChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles MainFrameBarManager1.CustomizingItemChanged
   ' Prevent a particular item from being Customized via Alt + Click.
   If Me.MainFrameBarManager1.CustomizingItem Is Me.ParentBarItem1 Then
      Me.MainFrameBarManager1.EndDragAndDropCustomizing()
   End If
End Sub 
'mainFrameBarManager1_CustomizingItemChanged
Private Sub Customization_Begin(ByVal sender As Object, ByVal e As System.EventArgs) Handles MainFrameBarManager1.CustomizationBegin
    ' Hide an item’s Category from appearing in the Customization Dialog.
    Me.MainFrameBarManager1.CategoriesToIgnoreInCustDialog.Add(Me.ParentBarItem1.CategoryIndex)
    ' Also hide the item itself.
    Me.ParentBarItem1.Visible = False
End Sub 
'Customization_Begin
Private Sub Customization_Done(ByVal sender As Object, ByVal e As System.EventArgs) Handles MainFrameBarManager1.CustomizationDone
   ' Unhide the item.
   Me.ParentBarItem1.Visible = True
   ' Make the category visible again in the customization dialog.
   Me.MainFrameBarManager1.CategoriesToIgnoreInCustDialog.Remove(Me.ParentBarItem1.CategoryIndex)
End Sub 'Customization_Done