Embed UIViewController Programmatically?

Question

I have a Storyboard setup with a UIViewController with an container view so that I can embed another UIViewController inside of it.

In a ce

Answer 1

You can do this by programmatically, below is the method which will take a bool value to make decision which view controller need to be added in container view and then will instantiate an object and after that will add it to containerView

- (void)addViewControllerToContainerView:(BOOL)addVC1
{
// Get storyboard
UIStoryboard *storyBoard = [UIStoryboard storyboardWithName:@"<name of storyboard>" bundle:[NSBundle mainBundle]];
    UIViewController *viewController = nil;
    if (addVC1)
    {
// get viewController with identifier 
        viewController = [storyBoard instantiateViewControllerWithIdentifier:@"<View Controller 1 Identifier>"];
    }
    else
    {
        viewController = [storyBoard instantiateViewControllerWithIdentifier:@"<View Controller 2 Identifier>"];
    }
// lets add it to container view
    [viewController willMoveToParentViewController:self];
    [self.view addSubview:viewController.view];
    [self addChildViewController:viewController];
    [viewController didMoveToParentViewController:self];
// keep reference of viewController which may be useful when you need to remove it from container view, lets consider you have a property name as containerViewController
    self.containerViewController = viewController;
}

When you need remove view controller from container view controller you can do this

   [self.containerViewController willMoveToParentViewController:nil];  // 1   
   self.containerViewController.view removeFromSuperView];
   [self.containerViewController removeFromParentViewController];//this line is updated as view is removed from parent view cotnroller istead of its viewcontroller is removed from parentViewController 
   self.containerViewController = nil

Apple docs about container view controllers

Answer 2

Swift version with UIPageViewController (which I believe is a common use case for this)

let pageController = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: nil)
// do your PageViewController stuff here (delegate and dataSource)
pageController.willMove(toParent: self)
containerView.addSubview(pageController.view)
pageController.view.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
            pageController.view.topAnchor.constraint(equalTo: containerView.topAnchor),
            pageController.view.bottomAnchor.constraint(equalTo: containerView.bottomAnchor),
            pageController.view.leadingAnchor.constraint(equalTo: containerView.leadingAnchor),
            pageController.view.trailingAnchor.constraint(equalTo: containerView.trailingAnchor)
])
addChild(pageController)
pageController.didMove(toParent: self)

I didn't figure out how to make use of the UIPageControll included in UIPageViewController so I ended up using my own instance. But I believe this is out of the scope of this question.