add UIViewController in subview

Question

I don't know if this is the right key to search "add UIViewController in subview". As what you can see in my image ,there are two ViewController, the main and the second controller. Inside the main controller there is a UIView(blue background color). Inside in UIView, I want to add the second ViewController in my UIView. I have this code but It didn't work.

here's my code

#import "ViewController.h"
#import "SampleViewController.h"
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIView *testView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    SampleViewController * sample = [[SampleViewController alloc] initWithNibName:@"SampleViewController" bundle:nil];
    sample.view.frame = CGRectMake(0, 0, self.testView.bounds.size.width, self.testView.bounds.size.height);
    [self.testView addSubview:sample.view];
} 

@end

I want to know if this is possible? I know initWithNibName: works in xib file, I don't the exact term to search in google about this. I'm just trying to experiment something if this is possible in IOS. Hoping you understand what I'm trying to do. Hoping for your advice. Thanks in advance

here's my update

@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIView *testView;
@property(strong,nonatomic) SampleViewController * samples;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

UIStoryboard *storyBoard = self.storyboard;
SampleViewController * sample = [storyBoard instantiateViewControllerWithIdentifier:@"SampleViewController"]; 
// SampleViewController * sample = [[SampleViewController alloc] //initWithNibName:@"SampleViewController" bundle:nil];

[self displayContentController:sample];
//commented the below line because it is not needed here, use it when you want to remove        
//child view from parent.
 //[self hideContentController:sample];

}

- (void) displayContentController: (UIViewController*) content;
{
    [self addChildViewController:content];                 // 1
    content.view.bounds = self.testView.bounds;                 //2
    [self.testView addSubview:content.view];
    [content didMoveToParentViewController:self];          // 3
}


- (void) hideContentController: (UIViewController*) content
{
    [content willMoveToParentViewController:nil];  // 1
    [content.view removeFromSuperview];            // 2
    [content removeFromParentViewController];      // 3
}

I always get this error

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Could not load NIB in bundle: 'NSBundle </Users/ace/Library/Developer/CoreSimulator/Devices/035D6DD6-B6A5-4213-9FCA-ECE06ED837EC/data/Containers/Bundle/Application/EB07DD14-A6FF-4CF5-A369-45D6DBD7C0ED/Addsubviewcontroller.app> (loaded)' with name 'SampleViewController''

I think, its looking for a nib. I didn't implement a nib here.

Answer 1

You should use Child containment concept, here MainViewController is a parent view controller and you want to add child view controller view as a subview on Main View Controller.

Adding and Removing a Child

//call displayContentController to add SampleViewCOntroller view to mainViewcontroller
 [self displayContentController:sampleVCObject];

// write this method in MainViewController
- (void) displayContentController: (UIViewController*) content;
{
   [self addChildViewController:content];                 // 1
   content.view.bounds = testView.bounds;                 //2
   [testView addSubview:content.view];
   [content didMoveToParentViewController:self];          // 3
}

Here’s what the code does:

It calls the container’s addChildViewController: method to add the child. Calling the addChildViewController: method also calls the child’s willMoveToParentViewController: method automatically. It accesses the child’s view property to retrieve the view and adds it to its own view hierarchy. The container sets the child’s size and position before adding the view; containers always choose where the child’s content appears. Although this example does this by explicitly setting the frame, you could also use layout constraints to determine the view’s position. It explicitly calls the child’s didMoveToParentViewController: method to signal that the operation is complete.

//you can also write this method in MainViewController to remove the child VC you added before.
- (void) hideContentController: (UIViewController*) content
{
   [content willMoveToParentViewController:nil];  // 1
   [content.view removeFromSuperview];            // 2
   [content removeFromParentViewController];      // 3
}

For more details, please refer to apple doc: https://developer.apple.com/library/content/featuredarticles/ViewControllerPGforiPhoneOS/ImplementingaContainerViewController.html

Configuring a Container in Interface Builder, for those who don't want to write code.

To create a parent-child container relationship at design time, add a container view object to your storyboard scene, as shown in Figure 5-3. A container view object is a placeholder object that represents the contents of a child view controller. Use that view to size and position the child’s root view in relation to the other views in the container.

When you load a view controller with one or more container views, Interface Builder also loads the child view controllers associated with those views. The children must be instantiated at the same time as the parent so that the appropriate parent-child relationships can be created.