Open UIViewController upon clicking on UITabbarItem

Question

I have created a UIViewController with a UITabbar in it.

I did not use UITabbarController because I wanted UITabbar on the top of the screen.

Upon clicking tab1, I want to present controller1 and on clicking tab2 I want to present controller 2. I don't want the tabbar to hide. I want to display the controller beneath the tabbar.

@interface MTLeaderFactoViewController () <UITabBarDelegate>
@property (weak, nonatomic) IBOutlet UITabBar *tabBar;
@end

@implementation MTLeaderFactoViewController

- (void)viewDidLoad {
    [super viewDidLoad];
}

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
}

- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item {
    if (item.tag == 0) {
        NSLog(@"item tag 0");
    } else {
        NSLog(@"item tag 1");
    }
}
@end

My questions:

1) didSelectItem method is not triggered even after using UITabbarDelegate

2) What is the most elegant way of displaying the controller when clicked on a button? I don't want to use segue as all the controllers are in different storyboards. For now, I plan to do

Controller1 *fp = [Controller1 controllerStoryboard:STORYBOARD_COURSE];
[self addChildViewController:fp];
[self.view addSubview:fp.view];
[fp didMoveToParentViewController:self];

EDIT 1:

    Controller1 *fp = [Controller1 controllerStoryboard:STORYBOARD_COURSE];
    [self addChildViewController:fp];
    [self.view addSubview:fp.view];
    [fp didMoveToParentViewController:self];

Tried this but it hides the tab bar. I want to utilize the space beneath the tab bar to display the controller

Answer 1

What you need to do is have a basecontroller class which will contain a tabbar(programatically created) then you can achive the desired output heres a sample baseController that i created,

import UIKit

class BaseViewController: UIViewController,UITabBarDelegate{

    override func viewDidLoad() {
        super.viewDidLoad()

        let myTabBar = UITabBar()
        myTabBar.frame = CGRect(x: 0, y: 60, width:self.view.frame.size.width, height: 50)

        let one = UITabBarItem()
        one.title = "one"
        one.tag = 1
        let two = UITabBarItem()
        two.title = "two"
        two.tag = 2
        myTabBar.setItems([one,two], animated: false)
        self.view.addSubview(myTabBar)
        myTabBar.delegate = self

    }


    func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {
        switch item.tag  {
        case 1:
            let controller = storyboard?.instantiateViewController(withIdentifier: "SecondViewController")
            addChildViewController(controller!)
            view.addSubview((controller?.view)!)
            controller?.didMove(toParentViewController: self)
            break
        case 2:
            let controller = storyboard?.instantiateViewController(withIdentifier: "ViewController")
            addChildViewController(controller!)
            view.addSubview((controller?.view)!)
            controller?.didMove(toParentViewController: self)
            break
        default:
            break
        }

    }

}

View Controller class :

import UIKit

class ViewController: BaseViewController {


    override func viewDidLoad() {
        super.viewDidLoad()
                // Do any additional setup after loading the view, typically from a nib.
    }


}

SecondView Controller :

import UIKit

class SecondViewController: BaseViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }



}

Answer 2

I would suggest using UITabBarController instead of UIViewController.

Add UITabViewController in your StoryBoard name it FirstTabBarController.

Add child view controller to FirstTabBarController. In all your child view of add UITabbar. Connect the TabBar delegate to each of your child ViewController.

Hide the default TabBar in your default FirstTabBarController.

- (void)viewWillAppear:(BOOL)animated {
     [super viewWillAppear:animated];
     self.tabBar.isHidden = true;
     [self setSelectedIndex:1];
  }

Add action to TabBar in your child ViewController as

- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item {
   NSUInteger index = [[theTabBar items] indexOfObject:item];
   NSLog(@"Tab index = %u", (int)indexO);
   [self.navigationController.tabBarController setSelectedIndex:index];
}

I would prefer this method over manually adding adding or removing ViewController as subview, let the UITabBarController manage that for you. Do let me know if you have further queries.