在没有 StoryBoard 的情况下点击通知时访问特定的 ViewController（以编程方式）

Question

I have an application that has 3 tabs: - Home - Inbox - Profile

When the user receives a notification, I want to open the correspond chat and when the user presses the back button, I want to be able to open the Inbox tab.

The following code that I have is this:

     func userNotificationCenter(_ center: UNUserNotificationCenter,
                                    didReceive response: UNNotificationResponse,
                                    withCompletionHandler completionHandler: @escaping () -> Void) {

            let notificationContent = response.notification.request.content

            switch notificationContent.categoryIdentifier {

            case "ChatViewController":

                let tabBarVC = self.window?.rootViewController as! MainTabViewController

                tabBarVC.selectedIndex = 1 // This is the Inbox tab

                let chatVC = ChatViewController(collectionViewLayout: UICollectionViewFlowLayout())

                let inboxVC = InboxViewController()

                inboxVC.navigationController?.pushViewController(chatVC, animated: true)

            default:
                return
            }


            completionHandler()
        }

However after this line tabBarVC.selectedIndex = 1 , the code is not read, and it opens the InboxViewController , why is that and how can I open the chat?

Answer 1

its too simple check for selected controller using

let selectedController = tabBarVC.selectedViewController? 

and full function

          func userNotificationCenter(_ center: UNUserNotificationCenter,
                                        didReceive response: UNNotificationResponse,
                                        withCompletionHandler completionHandler: @escaping () -> Void) {

                let notificationContent = response.notification.request.content

                switch notificationContent.categoryIdentifier {

                case "ChatViewController":

                    let tabBarVC = self.window?.rootViewController as! MainTabViewController

                    tabBarVC.selectedIndex = 1 // This is the Inbox tab

                    let chatVC = ChatViewController(collectionViewLayout: UICollectionViewFlowLayout())

              if let selectedController = tabBarVC?.selectedViewController as? InboxViewController
        {
            selectedController?.navigationController?.pushViewController(chatVC, animated: true)
        }               

                default:
                    return
                }


                completionHandler()
            }

Answer 2

func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {

        let notificationContent = response.notification.request.content

        switch notificationContent.categoryIdentifier {

        case "ChatViewController":

            let tabBarVC = self.window?.rootViewController as! MainTabViewController

            tabBarVC.selectedIndex = 1 // This is the Inbox tab

            let chatVC = ChatViewController(collectionViewLayout: UICollectionViewFlowLayout())

            if let selectedController = tabBarVC?.selectedViewController as? InboxViewController {
                selectedController?.navigationController?.pushViewController(chatVC, animated: true)
            } else if let nc =  tabBarVC?.selectedViewController as? UINavigationController {
                nc.pushViewController(chatVC, animated: true)
            }  

        default:
            return
        }


        completionHandler()
    }

// I have extended @Abu Ul Hassan's answer. As most probably the the selectedViewController will be a UINavigation controller.