Question

In UIViewControllers I have several methods such as viewDidLoad, viewWillAppear, viewDidAppear, etc.
The question is: “what is the best place to, for example, set the background color of my view, instantiate, and set the background color of a UILabel, or instantiate an object that I set as @property in my class and things like that? “

Thanks!

Answer 1

So many questions at once!

The first time the view is loaded, in viewDidLoad you will already have access to all the readily initialized UI elements, so it is a great place to configure the view and to set your class properties.

If you come back to the view if it is already loaded (say, by popping a view from a navigation controller, or dismissing a modal view controller), viewDidLoad will not be called. Thus, if you want to change something (background, add a label, change the background of a label, etc.) based on something that might have happened since the view controller was initialized, you have to use viewWillAppear.

You would use viewDidAppear if you want to animate a change so the user can see it after the view has already become visible.

Edit: this is pertinent for if you use IB or storyboard. See CitronEvanescent’s answer for the case that you create your view in code.