ios - 从 UITabBarController 初始化 viewController

Question

我有一个 UITabBarController。使用界面生成器我添加了多个 View Controller 。这些 viewControllers 都是同一个类，但唯一改变的是参数。

我想扩展 UITabBarController，以便在初始化 View Controller 时添加此参数，但我不知道如何在 UITabBarController 扩展中执行此操作。在哪里做这个合适的地方？？？

Answer 1

我也遇到过这样的问题，我想在标签栏 Controller 的第五个标签中显示弹出 View Controller ， 我用过这个:

func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {

    if(viewController == tabBarController.viewControllers?[4]){
        let storyboard : UIStoryboard = UIStoryboard(name: "AfterLogin", bundle: nil)
        let vc = storyboard.instantiateViewController(withIdentifier: "MorePopUpVC")
        vc.modalPresentationStyle = .popover
        let popover = vc.popoverPresentationController
        popover?.delegate = self
        popover?.permittedArrowDirections = .down
        popover?.sourceView = self.tabBar
        popover?.sourceRect = ((self.orderedTabBarItemViews()).last?.frame)!
        vc.preferredContentSize = CGSize(width: 120, height: 132)
        present(vc, animated: true, completion:nil)
        return false
    }
    return true
}

这就是我如何更改第五个选项卡的操作，

你可以像这样使用它:

func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {

        let storyboard : UIStoryboard = UIStoryboard(name: "YOUR STORYBOARD NAME", bundle: nil)
        let vc = storyboard.instantiateViewController(withIdentifier: "YOUR VIEW CONTROLLER IDENTIFIER")
        if(viewController == tabBarController.viewControllers?[4]){
            vc.type = "PARAMETER YOU WANT"
        }
        present(vc, animated: true, completion:nil)
        return false
}

我认为它有帮助。