如何从 TabBarController 传输数据

Question

如果它们之间仍然存在 NavigationController，如何将数据从 TabBarController 传输到其中的控制器

import UIKit

class MainTabBarViewController: UITabBarController {
    
    var currentUser: MUser = MUser(username: "fdff",
                                   usersurname: "dfdf",
                                   phone: "dffd",
                                   sex: "dfb",
                                   avatarStringURL: "fgf",
                                   id: "gf",
                                   bithDate: "fggf")
    
    override func viewDidLoad() {
        super.viewDidLoad()

        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let messageVC = self.navigationController?.viewControllers [3] as! MessageVC
        messageVC.currentUser = currentUser
 
    }

}

Answer 1

试试这个：

if let navigationController = viewControllers?[2] as? UINavigationController,
    let messageVC = navigationController.viewControllers.first as? MessageVC  {
    messageVC.currentUser = currentUser
}