ZIndex? of webCanvas or WebListBox?

I have a WebContainer that contains a WebListBox and a WebCanvas.
Depending on the view the WebListBox is disabled and invisible and the WebCanvas is enabled and visible or vise versa.
They both have the size dimensions and area on the WebContainer and shrink and grow together. i.e. they are superimposed within the came WebContainer.

Depending on the state of a radio group the WebListBox or WebCanvas is visible.
In the RadioGroup selection changed event, I set the visible/enabled attributes (and zindex) of the the WebListBox and WebCanvas.

I do see the ListBox appear and Disappear.

Is there a better way to do this?

I tend to only Enable/Disable rather than Enable/Visible/Disable/Invisible as it saves me having to resize objects or have ‘holes’ on screen.

Regarding the controls I use a Checkbox where there are two options only, or a popup menu if there are three or more options. Screen size can be a premium on the web app and radio buttons can take up a lot of horizontal and vertical space.