how to change UITabBarItem background colour on selection of it ?

    func tabBarController(tabBarController: UITabBarController, didSelectViewController viewController: UIViewController) {
//here 
}

class CustomTabBar: UITabBar {
    override func layoutSubviews() {
        super.layoutSubviews()

        // Change the background color of the selected tab bar item
        for item in self.items ?? [] {
            if let index = self.items?.firstIndex(of: item), let itemView = self.subviews[index+1] as? UIControl {
                itemView.backgroundColor = item.isSelected ? .red : .clear
            }
        }
    }
}

class MyTabBarController: UITabBarController {
    override func viewDidLoad() {
        super.viewDidLoad()

        // Create a custom tab bar and assign it to the tabBar property
        let customTabBar = CustomTabBar()
        self.setValue(customTabBar, forKey: "tabBar")

        // Add your view controllers here
    }
}