如何在更新UI时同时执行两个功能

Question

我正在实现In App purchases，它工作得很好。我同时实现了Auto-Renewable和Non-renewable订阅。我可以确定订阅活动和过期的时间。我可以根据订阅状态更新用户配置文件UI，但只能在一次选中一个时执行此操作。

如果我在视图即将出现时同时调用这两个functions。UI变得乱七八糟，无法显示正确的状态。我已经调试并看到，如果第一个检查一个订阅，更新其状态，当我移出view并回来时，它检查另一个返回到默认状态，即standard account，因为Auto-renewable已过期。有没有办法让我同时运行这两个函数，同时使用它们来更新我的UI。下面是我的代码。

var isUserActive: Bool?

var user: User {
    return AppDelegate.shared.user
}

func setUserAccountType() {
    if self.isUserActive == nil {
        self.userAccountType.text = ""
        self.userGoGold.isHidden = true
    } else {
        if self.isUserActive! {
            self.userAccountType.text = "Gold Account"
        } else {
            self.userAccountType.text = "Standard Account"
            self.userGoGold.isHidden = false
        }
    }
}

override func viewDidLoad() {
    super.viewDidLoad()
    self.setUserAccountType()
    IAPManager.shared.getProducts()
}

override func viewWillAppear(_ pAnimated: Bool) {
    super.viewWillAppear(pAnimated)
    self.checkForAutoRenewableSubscription()
    self.checkForNonRenewableSubscription()
}

func setUpUserAccountStatus(_ pIsActive: Bool) {
    DispatchQueue.main.async {
        self.isUserActive = pIsActive
        self.setUserAccountType()
        self.reloadRowForIdentifier(.billing)
        self.activityIndicator.hidesWhenStopped = true
        self.activityIndicator.stopAnimating()
    }
}

func checkForAutoRenewableSubscription() {
    self.activityIndicator.startAnimating()
    self.user.checkIfSubscriptionIsActive { (pIsActive) in
        self.setUpUserAccountStatus(pIsActive)
    }
}

func checkForNonRenewableSubscription() {
    self.activityIndicator.startAnimating()
    self.user.checkifNonRenewableSubscriptionIsActive { (pSubscribed) in
        self.setUpUserAccountStatus(pSubscribed)
    }
}

Answer 1

您需要使用DispatchGroup，并在它的notify部分中执行所需的操作

let dispatchGroup = DispatchGroup()
var inpIsActive = false
var inpSubscribed = false

func checkForAutoRenewableSubscription() {
    dispatchGroup.enter()
    self.activityIndicator.startAnimating()
    self.user.checkIfSubscriptionIsActive { (pIsActive) in
        self.inpIsActive = pIsActive   
        self.dispatchGroup.leave()
    }
}

func checkForNonRenewableSubscription() {
    dispatchGroup.enter()
    self.activityIndicator.startAnimating()
    self.user.checkifNonRenewableSubscriptionIsActive { (pSubscribed) in
        self.inpSubscribed = pSubscribed  
        self.dispatchGroup.leave()
    }
}

在viewDidLoad内部

checkForAutoRenewableSubscription()
checkForNonRenewableSubscription() 
dispatchGroup.notify(queue: .main) { 
   self.setUpUserAccountStatus()
}