How to open alertcontroller after pressed TabBar?-CodePudding

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import UIKit

class TabBarController: UITabBarController, UITabBarControllerDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .white
        self.delegate = self
        
        let vc1 = UINavigationController(rootViewController: VideoListVC())
        let vc2 = UINavigationController(rootViewController: AddViewController())
        let vc3 = UINavigationController(rootViewController: FabricViewController())
        
        
        
        vc1.tabBarItem.image = UIImage(systemName: "house")
        vc2.tabBarItem.image = UIImage(systemName: "qrcode")
        vc3.tabBarItem.image = UIImage(systemName: "house")
        
        
        
        //tabBar.tintColor = .label
        
        setViewControllers([vc1, vc2, vc3], animated: true)
        
        
        func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UITabBarController) {
                if viewController is AddViewController {
                    print("Alert is opened")
                
            }
       

    }

I can't open alertcontroller because my TabBarController is rootcontroller. How can i fix it ?

CodePudding user response：

the didSelect method is wrong , replace with :

func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
        if viewController is AddViewController {
            print("put code for showing alert")
        }
    }

CodePudding user response：

Just cross check you delegate function with the below code

   func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
        if let vc = viewController as? UINavigationController, vc.topViewController! is AddViewController {
            let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: .alert)
            alert.addAction(UIAlertAction(title: "Ok", style: .default))
            self.present(alert, animated: true)
        }
    }

Since you are adding UINavigationController to the UITabBarController, so first you need to check for that inside the delegate function and then check for the rooviewcontroller of the UINavigationController.

CodePudding user response：

self.show(alertController, sender: self)

This should work as UITabbarController is a subclass of UIViewController