viewController.view not getting added to custom view inside Parent View Controller - ios

Question

I would like to add a childViewController into a custom UIView part of a parentViewController. However, if I am doing self.customView.addSubview(childViewController.view) I cannot see the childViewController.view as it doesn't get added. In contrast, if I do self.view.addSubview(childViewController.view) it all works well. Can someone explain why this is happening? I really need to add childViewController.view as subview of the customView and not as part of the self.view.
if let childViewController = self.storyboard?.instantiateViewController(withIdentifier: "ChildVC") as UIViewController? {
self.addChildViewController(childViewController)
childViewController.view.frame = customView.bounds
self.customView.addSubview(childViewController.view)
childViewController.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
childViewController.didMove(toParentViewController: self)
childViewController.view.frame = CGRect(x: customView.frame.origin.x,
y: customView.frame.origin.y,
width: customView.frame.width,
height: customView.frame.height)
}

Answer 1

How about using a Container view from Object Library (place from where we drag table view, textView and all UI components onto our storyboard). which is
Container view define a region of view controller that include
a child view controller
When you take Container view from object library in your desired
ViewController on storyBoard.
it automatically gives you a another view controller attached to your view controller with a segue.
you just need to override this segue code and that dragged container view will work as a child view controller for you it did load will call automatically.
just Override this is your parent view Controller
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let identifier = segue.identifier {
switch identifier {
case "SegueIndetifierName":
(segue.destination as? YourChildViewController)?.parentViewControllerObject = self
default:
break
}
}
}
NOTE: declare parentView controller object in your child view controller like this
weak var parentViewControllerObject: ParentViewController!
to uniquely identify the relation ship between child and parent. and rest your work will be done automatically.

Answer 2

You can check the Sample Working project to add Subviews
Link https://github.com/RockinGarg/Container_Views.git
Required Code:
Class Object to be added as Subview
private lazy var FirstObject: firstVC =
{
// Instantiate View Controller
let viewController = self.storyboard?.instantiateViewController(withIdentifier: "firstVC") as! firstVC
// Add View Controller as Child View Controller
self.addChildViewController(viewController)
return viewController
}()
Add in ParentView as Subview
private func add(asChildViewController viewController: UIViewController)
{
// Configure Child View
viewController.view.frame = CGRect(x: 0, y: 0, width: self.firstContainer.frame.size.width, height: self.firstContainer.frame.size.height)
// Add Child View Controller
addChildViewController(viewController)
viewController.view.translatesAutoresizingMaskIntoConstraints = true
// Add Child View as Subview
firstContainer.addSubview(viewController.view)
// Notify Child View Controller
viewController.didMove(toParentViewController: self)
}
Where : -
firstContainer is the parent view In which subview is to be added
viewController class object whose view is to be added as Subview
Note- This can be used in containerViews as well as Normal UIView too for adding a Controller as Subview