The Zoom is untouched when the (TImageEnView) component changes its sizes. I suppose you Want to change the Zoom on resizing, to adapt the image size (Zoom) to the component size. Isn't it? In this case there are several options, depending how you need to adapt image size to the component size. The simplest is to set: ImageEnView.AutoFit=true.
Well, kind of. I guess if the image was filling the entire component, i would like to be the same when i maximize. So i would need to know if i had imageenview.fit before the resize to re apply it after. if not, then i do not want to do anything as you are telling me that the zoom ratio des not change. If i set autofit to true, i think i cannot zoom anymore if i recall. Maybe i am getting too complicated.
This is specific of application logic. Of course you can obtain the same effect of AutoFit calling Fit(). Maybe you should place a flag to know when the user changed zoom (and scroll?) manually, to avoid to call Fit().