IOS AppDelegate控制器或令牌中的变量

Question

我完全{fresh / beginner}应用程序开发人员，如果我问任何愚蠢的问题，请耐心等待。

我试图在我的应用程序运行时在我的故事板上显示令牌。如果你检查我的代码。当我运行应用程序时，我已经创建了委托变量var tokenVal = ""我在我的故事板上没有任何价值，但是它在控制台中的打印令牌。

第二期虽然正在编译和运行，但仍会显示警告。

这是我的问题AppDelegate.swift代码

import UIKit
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var tokenVal = ""
    var window: UIWindow?


func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.

    registerPushNotifications()

    return true
}


func registerPushNotifications() {
    DispatchQueue.main.async {
        let settings = UIUserNotificationSettings(types: [.badge, .sound, .alert], categories: nil)
        UIApplication.shared.registerUserNotificationSettings(settings)
    }
}

func application(_ application: UIApplication, didRegister notificationSettings: UIUserNotificationSettings) {
    if notificationSettings.types != UIUserNotificationType() {
        application.registerForRemoteNotifications()
    }
}




func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    var token = ""
    for i in 0..<deviceToken.count {
        token = token + String(format: "%02.2hhx", arguments: [deviceToken[i]])
    }

    tokenVal = token
    print(token)
}



func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: NSError) {
    print("Registration failed!")
}


func applicationWillResignActive(_ application: UIApplication) {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
}

func applicationDidEnterBackground(_ application: UIApplication) {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

func applicationWillEnterForeground(_ application: UIApplication) {
    // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
}

func applicationDidBecomeActive(_ application: UIApplication) {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

func applicationWillTerminate(_ application: UIApplication) {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}


}

ViewController.swift代码

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var TokenLb: UILabel!
    @IBOutlet weak var tokenVarVal: UILabel!
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        let appDelegate = UIApplication.shared.delegate as! AppDelegate
        //let aVariable = appDelegate.
        let bVariable = appDelegate.tokenVal
        tokenVarVal.text = bVariable
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

Answer 1

这是操作顺序的简单问题。在视图控制器的tokenVal运行之后，应用程序代理viewDidLoad正在设置。

（通常，使用一个类的属性作为另一个类的“drop”以便稍后获取值是一种笨拙的策略。如果另一个类需要此值，给值< em> to 另一个班级。）