Shall I really use addChildViewController when I add a view to another view (and both these views are controlled by view controllers)?

问题

I am building a UIViewController with a XIB. In this XIB, I have placeholders (UIView objects in the XIB) in which I place other views, from other view controllers. (By the way, I could also add these views directly, without placeholders)

I am not buiding a container view controller: I mean it's not a UINavigationController. It's a just a "usual" view controller. Imagine for example that I have a small subview in my view for a "Facebook" logo and a counter. This "facebook view" is attached to another view controller that is called when the "Facebook view" is touched. So, the "Facebook controller" definitely needs to be a @property of my "main" view controller.

In this situation, should I really use addChildViewController: and all the mechanism? Or no?

Thanks!

回答1:

You should not be using a UIViewController merely to "fish" into a .xib file for you to obtain the view. If that's all you want it for, don't do that. Just load the nib and pull out the view, directly:

NSArray* objects = [[UINib nibWithNibName: @"MyNib" bundle: nil]
            instantiateWithOwner:nil options:nil];
UIView* v = (UIView*)[objects firstObject];

But if you are using a UIViewController in conjunction with this .xib file for some other reason, e.g. to keep it alive so that a button inside the .xib can send messages to this UIViewController, then absolutely you must make a proper parent-child relationship, as I describe in my book: http://www.apeth.com/iOSBook/ch19.html#_container_view_controllers

回答2:

Yes, you should. By doing so, the containing view controller sends proper view controller lifecycle events to the child view controllers.

You say you aren't building a container view controller but you are. Adding the view of another view controller to another view controller is the definition of a container view controller.

See the "Implementing a Container View Controller" section of the docs for UIViewController on the proper sequence of method calls you should make. It's more than just calling addChildViewController.

回答3:

You can instantiate your insider ViewController, and just add its view (myInsiderViewController.view) to your main viewController:

[mainViewController.view addSubView:myInsiderViewController.view];

来源：https://stackoverflow.com/questions/29973948/shall-i-really-use-addchildviewcontroller-when-i-add-a-view-to-another-view-and