ios - SwiftUI View 中的 StoreKit 委托(delegate)/可观察对象

Question

当我恢复购买时，我需要禁用 View 中的恢复按钮。

我有 IAPManager 类和 SKPaymentTransactionObserver，它工作正常，我在调用时看到了 SKPaymentTransactionObserver 的 print("restored") SKPaymentQueue.default().restoreCompletedTransactions 从我的主要观点来看。

那么问题是，从 View 中我没有发现该事件，因此我无法禁用该按钮，因为购买已经恢复。

在我的 IAPManager 中:

func restore(withUsername username: String? = nil) {
    SKPaymentQueue.default().add(self)
    SKPaymentQueue.default().restoreCompletedTransactions(withApplicationUsername: username)
}

extension IAPManager: SKPaymentTransactionObserver {

func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
    transactions.forEach {
        switch $0.transactionState {
        case .purchasing: ()
            print("purchasing")
        case .deferred: ()
            print("deferred")
        case .restored: SKPaymentQueue.default().finishTransaction($0)
            print("restaured")
                UserDefaults.standard.set(true, forKey: "pro")
        case .failed: SKPaymentQueue.default().finishTransaction($0)
            print("failed")
                UserDefaults.standard.set(false, forKey: "pro")
        case .purchased: SKPaymentQueue.default().finishTransaction($0)
            print("purchased")
                UserDefaults.standard.set(true, forKey: "pro")
        @unknown default:
            break
        }
    }

}

在我看来:

Text("Available purchases").font(.title3).foregroundColor(.green)
  .onTapGesture {
    IAPManager.shared.getProducts()
  }.padding()
Spacer()
  Button(action: {
    let purchased = UserDefaults.standard.bool(forKey: "pro")
    if !purchased {
        print("Going to try restore")
        IAPManager.shared.restore()
    } else {
        print("restored!")
    }
  }){
    Text((buyed ? "Restored"  : "Restore" ))
        .fontWeight(.bold)
           .font(.none)
           .padding(6)
           .cornerRadius(40)
           .foregroundColor(.blue)
           .overlay(
               RoundedRectangle(cornerRadius: 40)
                .stroke(Color.blue, lineWidth: 0.8)
           )
  }.buttonStyle(PlainButtonStyle())
  .disabled(  UserDefaults.standard.bool(forKey: "pro"))
  .padding()

Answer 1

对于不相关和已经存在的组件之间的通信，您可以使用自定义通知。

1. 为您的通知创建一个名称:

extension IAPManager {
    static let proNotification = Notification.Name(rawValue: "proNotification")
}

1. 在您恢复交易的地方，发送通知，通知所有订阅者 Pro 已恢复:

case .restored: 
    print("restored")
    SKPaymentQueue.default().finishTransaction($0)
    NotificationCenter.default.post(name: IAPManager.proNotification, object: nil, userInfo: nil)

1. 现在您需要一种方法来观察此通知::

struct ContentView: View {
    @State var isPro = false
    
    var body: some View {
        Text(isPro ? "pro user" : "standard user")
            .onReceive(NotificationCenter.default.publisher(for: IAPManager.proNotification)) { _ in
                self.isPro = true
            }
    }
}