Question

I have a button that open another viewController(familyView) when clicked.
In familyView there is another button which suppose to bring me back to the mainViewController(ViewController.xib) but I don’t know how to call the main viewController.

My method to call familyView

UIViewController* familyView = [[UIViewController alloc] initWithNibName:@"familyView" bundle:[NSBundle mainBundle]];
[self.view addSubview:familyView.view];

I hope you could help on how to call the main ViewController ? do I have to use the same method to call it? like this I mean:

UIViewController* mainView = [[UIViewController alloc] initWithNibName:@"viewController" bundle:[NSBundle mainBundle]];
[self.view addSubview:mainView.view];

If yes, is there a better way to implement this? in my demo project, I’m trying to make 7 views full with data and a button to go back and forth.

EDIT:
If I use UIView would that be best for me instead of using different viewControllers with their implementations and interfaces files?
My project will have views, and each view has data on it parsed from a different html page.

Answer 1

There are two method that can be used.

1. UINavigationController
2. Delegates

From your question it seems that a UINavigationController is the best option but I will show you both.

---

UINavigationController

When you load your mainViewController from your app delegate your going to need to wrap it in a nav controller like so:

AppDelegate.h

@property (strong, nonatomic) UINavigationController *navController;

AppDelegate.m

@synthesize navController = _navController;

//in didFinishLaunchingWithOptions:

UIViewController *mainViewController = [[MainViewController alloc] initWithNibName:@"MainViewController" bundle:nil];

navController = [[UINavigationController alloc] initWithRootViewController:mainViewController];

self.window.rootViewController = nav1;
[self.window makeKeyAndVisible];

Now in your MainViewController you have the convince of UINavigationController.

When you want to push to a child from a parent you can simply do:

ChildViewController *child = [[ChildViewController alloc]...];
[self.navigationController pushViewController:child animated:YES];

If you in your ChildViewController and want to go back simply do:

[self.navigationController popViewControllerAnimated:YES];

This is the “Drill Down” technique.

(I know “Drill Down” has more meaning than simply that but it provides a good frame of reference.)

---

Delegate

Now the other method that you have is to setup delegates between the classes. So if your in childView and need to call your parent, you will have a channel to do so.

In your MainViewController.h setup it like so:

#import <UIKit/UIKit.h>

//This is our delegate
@protocol TalkToParentDelegate <NSObject>

//This is our delegate method
- (void)helloParent;
@end

@interface MainViewController : UIViewController <TalkToParentDelegate> 
...
..
@end

In your MainViewController.m make sure add the delegate method.

- (void)helloParent {
  NSLog(@"Hello child, let me do something here");
}

In your ChildViewController.h setup it like so:

#import <UIKit/UIKit.h>

//Add header of class where protocol was defined
#import "MainViewController.h"

@interface ChildViewController : UIViewController

//Create a property we can set to reference back to our parent
@property (strong, nonatomic) id <TalkToParentDelegate> delegate;

@end

Now, in your MainViewController.m , whenever you present your ChildViewController do this:

ChildViewController *child = [[ChildViewController alloc]...];

//Set the delegate reference to parent 
child.delegate = self;

//present the view

Last but not least, no when you in your child you can call methods on your parent (MainViewController) like so:

[self.delegate helloParent];

---

So here are two methods that you can use.

I would like to note however, you can use these together. Say you had a UINavigationController but still needed a child to talk to its parent, you can setup a delegate so that’s possible.

• Hope this helps.