Switch container view dynamically

Question

I\'m using a storyboard container view. So I have a view controller containing a container view. I have a second, smaller view in the storyboard, which is embedded in that c

Answer 1

rdelmar's answer converted to Swift syntax

    override func viewDidLoad() {
        super.viewDidLoad()

        self.initialVC = self.childViewControllers.last
        self.substituteVC = self.storyboard!.instantiateViewControllerWithIdentifier("Substitute")
        self.currentVC = self.initialVC;

}
    @IBAction func switchControllers(sender: UISegmentedControl) {
        switch sender.selectedSegmentIndex{
            case 0:
                if (self.currentVC == self.substituteVC) {
                    self.addChildViewController(self.initialVC)
                    //self.initialVC.view.frame = self.containerView.bounds
                    moveToNewController(self.initialVC)
                }
            case 1:
                if (self.currentVC == self.initialVC) {
                    self.addChildViewController(self.substituteVC)
                    //self.substituteVC.view.frame = self.containerView.bounds
                    moveToNewController(self.substituteVC)
                }
            default:
            break;
        }
    }

    func moveToNewController(newController : UIViewController){
        self.currentVC.willMoveToParentViewController(nil)
        self.transitionFromViewController(
            self.currentVC!,
            toViewController: newController,
            duration: 0.2,
            options: UIViewAnimationOptions.TransitionCrossDissolve,
            animations: nil,
            completion: { finished in
                self.currentVC.removeFromParentViewController()
                newController.didMoveToParentViewController(self)
                self.currentVC = newController
        })

    }

Answer 2

You need to use the custom container view controller api to do the switching of the controllers. The following code shows one way to do that. In this project I had a segmented control in the main view controller (the one with the container view) that switches beetween the two controllers. initialVC is the controller that's embedded in IB, and substituteVC is the one I'm switching to. The property, container, is an IBOutlet to the container view.

- (void)viewDidLoad {
    [super viewDidLoad];
    self.initialVC = self.childViewControllers.lastObject;
    self.substituteVC = [self.storyboard instantiateViewControllerWithIdentifier:@"Substitute"];
    self.currentVC = self.initialVC;
}

-(IBAction)switchControllers:(UISegmentedControl *)sender {

    switch (sender.selectedSegmentIndex) {
        case 0:
            if (self.currentVC == self.substituteVC) {
                [self addChildViewController:self.initialVC];
                self.initialVC.view.frame = self.container.bounds;
                [self moveToNewController:self.initialVC];
            }
            break;
        case 1:
            if (self.currentVC == self.initialVC) {
                [self addChildViewController:self.substituteVC];
                self.substituteVC.view.frame = self.container.bounds;
                [self moveToNewController:self.substituteVC];
            }
            break;
        default:
            break;
    }
}


-(void)moveToNewController:(UIViewController *) newController {
    [self.currentVC willMoveToParentViewController:nil];
    [self transitionFromViewController:self.currentVC toViewController:newController duration:.6 options:UIViewAnimationOptionTransitionFlipFromLeft animations:nil
                            completion:^(BOOL finished) {
                                [self.currentVC removeFromParentViewController];
                                [newController didMoveToParentViewController:self];
                                self.currentVC = newController;
                            }];
}

After Edit:

If you want to go to the new controller with no animation, you can do it like this (this substitutes for the code that I had under case 1).

[self addChildViewController:self.substituteVC];
[self.substituteVC didMoveToParentViewController:self];
self.substituteVC.view.frame = self.container.bounds;
[self.container addSubview:self.substituteVC.view];
[self.currentVC removeFromParentViewController];

Answer 3

If you deal with more than 2 child view controllers it's a good idea to store them in array. Also, you'll need to apply constraints every time you add a new subview to the container view. Here's a modified version of the accepted answer (using Swift 2 syntax):

import UIKit

class FooBarViewController: UIViewController
{
    // MARK: - IBOutlets

    @IBOutlet weak var containerView: UIView!

    // MARK: - Properties

    var vcs = [UIViewController]()
    var currentVC: UIViewController!

    // MARK: - ViewController Lifecycle

    override func viewDidLoad()
    {
        super.viewDidLoad()

        vcs.append(childViewControllers.last!)
        vcs.append(storyboard!.instantiateViewControllerWithIdentifier("FooViewControler"))       
        vcs.append(storyboard!.instantiateViewControllerWithIdentifier("BarViewController"))
        currentVC = vcs[0]

        for vc in vcs {
            vc.view.frame = containerView.bounds
        }
    }

    // MARK: - Methods

    func switchToViewController(targetVC: UIViewController)
    {
        addChildViewController(targetVC)
        currentVC.willMoveToParentViewController(nil)

        transitionFromViewController(
            currentVC,
            toViewController: targetVC,
            duration: 0.0, // 0.3
            options: .TransitionNone, // .TransitionCrossDissolve,
            animations: nil,
            completion: { finished in
                self.currentVC.removeFromParentViewController()
                targetVC.didMoveToParentViewController(self)
                self.currentVC = targetVC
                self.applyConstraints()
        })
    }

    func applyConstraints()
    {
        let viewsDict = ["newSubview": currentVC.view]

        currentVC.view.translatesAutoresizingMaskIntoConstraints = false

        containerView.addConstraints(
            NSLayoutConstraint.constraintsWithVisualFormat("H:|[newSubview]|",
                options: NSLayoutFormatOptions(rawValue: 0),
                metrics: nil,
                views: viewsDict))

        containerView.addConstraints(
            NSLayoutConstraint.constraintsWithVisualFormat("V:|[newSubview]|",
                options: NSLayoutFormatOptions(rawValue: 0),
                metrics: nil, views:
                viewsDict))
    }

    // MARK: - IBActions

    @IBAction func switchControllers(sender: UISegmentedControl)
    {
        let i = sender.selectedSegmentIndex

        if currentVC != vcs[i] {
            self.addChildViewController(vcs[i])
            switchToViewController(vcs[i])
        }
    }
}