I've set up multiple sets of constraints in IB, and I'd like to programmatically toggle between them depending on some state. There's a
constraintsA outlet collection all of which are marked as installed from IB, and a
constraintsB outlet collection all of which are uninstalled in IB.
I can programmatically toggle between the two sets like so:
But... I can't figure out when to do that. It seems like I should be able to do that once in
viewDidLoad, but I can't get that to work. I've tried calling
view.layoutSubviews() after setting the constraints, but to no avail.
I did find that if I set the constraints in
viewDidLayoutSubviews everything works as expected. I guess I'd like to know two things...
- Why am I getting this behavior?
- Is it possible to activate/deactivate constraints from viewDidLoad?