保留标签栏时在AppDelegate中打开ViewController

Question

在我的Xcode项目中，当用户点击通知时，我想先将其发送到tabBar中的某个项目，然后再实例化视图控制器并将对象发送到该视图控制器。我有将它们发送到所需的tabBar的代码，但我不知道如何在将tabBar和导航栏保持与视图控制器连接的同时将它们实例化到视图控制器。关于此问题的所有答案都需要您更改根视图控制器，这使我在调用视图控制器时失去了与tabBar和导航栏的连接。

一个真实的例子： 用户收到Instagram通知，说“ John开始关注您”->用户点击通知->
Instagram打开并显示通知选项卡->快速将用户发送到“ John”个人资料，并在用户按下后退按钮时，它将它们发送回通知标签

应该知道：我首先要进入某个选项卡的原因是要获取该选项卡的导航控制器，因为我要使用的视图控制器没有该控制器。

这是我将用户发送到“通知”选项卡的工作代码（我添加了注释，使其与Instagram示例类似，以便更好地理解）：

if let tabbarController = self.window!.rootViewController as? UITabBarController {
    tabbarController.selectedViewController = tabbarController.viewControllers?[3] //goes to notifications tab
    if type == "follow" { //someone started following current user                            
        //send to user's profile and send the user's id so the app can find all the information of the user                    
    }
}

Answer 1

首先，您需要使TabBarController满足需要：

let storyboard = UIStoryboard.init(name: "YourStoryboardName", bundle: nil)
let tabBarController = storyboard.instantiateViewController(withIdentifier: "YourTabBarController") as! UITabBarController

然后充分满足所有viewControllersTabBarController的需求。如果您的viewControllers嵌入到UINavigationController？如果是这样，您将改为使用导航控制器：

let first = storyboard.instantiateViewiController(withIdentifier: "YourFirstNavigationController") as! UINavigationController
let second = storyboard.instantiateViewiController(withIdentifier: "YourSecondNavigationController") as! UINavigationController
let third = storyboard.instantiateViewiController(withIdentifier: "YourThirdNavigationController") as! UINavigationController

另外，您也应该实例化所需的ViewController：

let desiredVC = storyboard.instantiateViewController(withIdentifier: "desiredVC") as! ExampleDesiredViewController

viewControllers从TabBarController开始制作所有NavigationControllers ：

tabBarController.viewControllers = [first, second, third]

并检查：这取决于您的选择。

if tabBarController.selectedViewController == first {

// Option 1: If you want to present
first.present(desiredVC, animated: true, completion: nil)

// Option 2: If you want to push
first.pushViewController(desiredVC, animated. true)

}

将tabBarController设置为rootViewController：

self.window = UIWindow.init(frame: UIScreen.main.bounds)   
self.window?.rootViewController = tabBarController
self.window?.makeKeyAndVisible()

最后：这是您完成的代码：

func openViewController() {

let storyboard = UIStoryboard.init(name: "YourStoryboardName", bundle: nil)
let tabBarController = storyboard.instantiateViewController(withIdentifier: "YourTabBarController") as! UITabBarController

let first = storyboard.instantiateViewiController(withIdentifier: "YourFirstNavigationController") as! UINavigationController
let second = storyboard.instantiateViewiController(withIdentifier: "YourSecondNavigationController") as! UINavigationController
let third = storyboard.instantiateViewiController(withIdentifier: "YourThirdNavigationController") as! UINavigationController

let desiredVC = storyboard.instantiateViewController(withIdentifier: "desiredVC") as! ExampleDesiredViewController

tabBarController.viewControllers = [first, second, third]

if tabBarController.selectedViewController == first {

// Option 1: If you want to present
first.present(desiredVC, animated: true, completion: nil)

// Option 2: If you want to push
first.pushViewController(desiredVC, animated. true)

}

self.window = UIWindow.init(frame: UIScreen.main.bounds)   
self.window?.rootViewController = tabBarController
self.window?.makeKeyAndVisible()

}

如果要在点击通知时显示或推送ViewController？尝试这样的事情：

extension AppDelegate: UNUserNotificationCenterDelegate {

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

        switch response.actionIdentifier {
        case UNNotificationDefaultActionIdentifier:
            openViewController()
            completionHandler()

        default:
            break;
        }
    }
}