>Hi All.
>
>I create a SDI form, About 100 objects in 20 containers of it. These containers contain some custom class . They have the same Width, Length, Top, Left attributes. When container A is displaying, the others will be covered by A. I switch them with their ZOrder(0) method to bring one of them to front in this form.
>
>Most of objects in this form have their own MouseMove event code to show a ToolTipText-Like Label object, I move it depend on mouse pointer's coordinate.
>
>When I start the form, It runs good. but after I subclass(use AddObject method) more custom class in it, the performance is slow down.
>
>Could anybody help me?

What if you will use RemoveObject (instead of overlapping containers). You may also consider pageframe design.