StoreKit 2：如何通过.subscriptionStatusTask识别订阅组内有效订阅

问题 #

我用SubscriptionStoreView搭配.onInAppPurchaseCompletion、.subscriptionStatusTask、.manageSubscriptionSheet实现同一订阅组内的月付、年付自动续期订阅（无其他内购类型）。

现在卡在.subscriptionStatusTask的使用上：怎么在这个闭包里准确识别用户实际购买的订阅？之前我通过返回值映射，读取transaction.payloadValue判断，但当月付升级年付后，transaction.payloadValue.productID还是显示月付（推测是月付尚未到期），但我的应用需要根据用户是否购买年付来开放更多功能，仅靠.subscriptionStatusTask该怎么实现？

补充测试现象：月付升级年付后，prodId仍显示月付，但Debug→StoreKit→Manage Transactions里显示月付将于9-7-24到期，年付会续订；取消年付时，提示可使用至2024年9月7日，取消后交易记录显示月付但不再续订。

还有几个疑问：

• 通过.manageSubscriptionSheet变更订阅时，购买是否即时生效？
• 是否需要读取续订信息来提前开放年付功能，用户取消续订则恢复月付权限？
• 还有哪些要点我未考虑到？

附测试代码：

struct ContentViewSO2: View {
@State private var paywallShown = false
@State private var isPro = false
@State private var presentingSubscriptionSheet = false
@State private var showManageSubscriptionButton = false

@State private var subType = ""

var body: some View {
    VStack(spacing: 75){
        Text("Testing Store Paywall and Subscription Status Sheet")
            .multilineTextAlignment(.center)
            .foregroundColor(.black)
            .font(.system(size: 18, weight: .heavy, design: .rounded))
            .padding(.vertical, 75)
            .subscriptionStatusTask(for: "C5FF4E1D") { taskState in
                if let value = taskState.value {
                    
                    //.. check to see if there was EVER a subscription in order to know whether or not to present the .manageSubscriptionSheet. It seems that if there was never a subscription, the .manageSubscriptionSheet will not appear... it just clocks
                    
                    if value.count > 0 {
                        showManageSubscriptionButton = true
                    } else {
                        showManageSubscriptionButton = false
                    }
                    
                    let _: [()] = value.map { status in
                        //.. transaction = what's currently purchased???????
                        
                        let statusTransaction = status.transaction
                        let payloadValue =  try? status.transaction.payloadValue
                        let prodId = payloadValue?.productID
                        print("product id = \(prodId)")
                        
                        if prodId == "com.HR.test.yearly" {
                            subType = "yearly"
                        } else if prodId == "com.HR.test.monthly" {
                            subType = "monthly"
                        } else {
                            subType = "none"
                        }
                        
                        //.. if there is a value that's not .revoked and not .expired
                        isPro = !value
                            .filter { $0.state != .revoked && $0.state != .expired }
                            .isEmpty
                        
                        //.. for more debugging
                        let renewalState = status.state
                        switch renewalState {
                        case .revoked:
                            print("renewalState = revoked")
                        case .expired:
                            print("renewalState = expired")
                        case .subscribed:
                            print("renewalState = subscribed")
                        case .inBillingRetryPeriod:
                            print("renewalState = inBillingRetryPeriod")
                        case .inGracePeriod:
                            print("renewalState = inGracePeriod")
                        default:
                            print("renewalState = ???")
                        }
                    }
                }
            }
        isPro ?
        Text("IS PRO FROM .subscriptionStatusTask")
            .foregroundColor(.white)
            .background(Color.green)
        :
        Text("IS NOT PRO FROM .subscriptionStatusTask")
            .foregroundColor(.white)
            .background(Color.red)
        
        switch subType {
        case "monthly":
            Text("Monthly Subscription")
                .padding(.horizontal, 25)
                .foregroundColor(.white)
                .background(Color.blue)
        case "yearly":
            Text("Yearly Subscription")
                .padding(.horizontal, 25)
                .foregroundColor(.white)
                .background(Color.teal)
        default:
            Text("No Subscription")
                .padding(.horizontal, 25)
                .foregroundColor(.white)
                .background(Color.red)
        }
        
        //.. check to see if there was EVER a subscription in order to know whether to present the .manageSubscriptionSheet. It seems that if there was never a subscription, the .manageSubscriptionSheet will not appear... it just clocks. If there has not been any subscription EVER, show paywall instead of manage subscription sheet

        if !showManageSubscriptionButton {
            Button(action: {
                paywallShown = true
            }, label: {
                Text("Press to test paywall")
            })
            .buttonStyle(.borderedProminent)
            .sheet(isPresented: $paywallShown) {
                HRShop()
            }
        } else {
            Button(action: {
                self.presentingSubscriptionSheet = true
            }, label: {
                Text("Show .manageSubScriptionSheet")
            })
            .manageSubscriptionsSheet(
                isPresented: $presentingSubscriptionSheet,
                subscriptionGroupID: "C5FF4E1D"
            )
        }
    }
    Spacer()
}
}

解决方案 #

1. 优先读取latestSubscriptionInfo而非当前交易 #

用户升级/降级订阅时，当前生效的订阅未到期，但StoreKit已记录下一次续订的产品信息。要从SubscriptionStatus的latestSubscriptionInfo字段获取用户当前的订阅意愿（即将生效的产品），而不是仅依赖当前交易的payloadValue.productID。

修改后的.subscriptionStatusTask逻辑：

.subscriptionStatusTask(for: "C5FF4E1D") { taskState in
    guard let statuses = taskState.value else {
        showManageSubscriptionButton = false
        isPro = false
        subType = "none"
        return
    }
    
    showManageSubscriptionButton = !statuses.isEmpty
    
    // 筛选有效订阅状态（未过期、未撤销）
    let activeStatuses = statuses.filter {
        $0.state != .revoked && $0.state != .expired
    }
    
    isPro = !activeStatuses.isEmpty
    
    // 遍历有效状态，优先用latestSubscriptionInfo判断订阅类型
    for status in activeStatuses {
        if let latestInfo = status.latestSubscriptionInfo {
            let prodId = latestInfo.productID
            print("Latest subscription product ID: \(prodId)")
            
            subType = prodId == "com.HR.test.yearly" ? "yearly" : "monthly"
        } else {
            // 无续订计划时，回退到当前交易的产品ID
            if let payloadValue = try? status.transaction.payloadValue {
                subType = payloadValue.productID == "com.HR.test.yearly" ? "yearly" : "monthly"
            } else {
                subType = "none"
            }
        }
    }
    
    // 调试订阅状态
    for status in statuses {
        switch status.state {
        case .revoked: print("renewalState = revoked")
        case .expired: print("renewalState = expired")
        case .subscribed: print("renewalState = subscribed")
        case .inBillingRetryPeriod: print("renewalState = inBillingRetryPeriod")
        case .inGracePeriod: print("renewalState = inGracePeriod")
        default: print("renewalState = ???")
        }
    }
}

2. 订阅变更的即时性与权限处理 #

• 即时开放权限：用户通过.manageSubscriptionSheet完成升级后，latestSubscriptionInfo会立即更新为年付产品ID，可直接据此开放年付功能，无需等待当前月付到期。
• 取消续订后恢复权限：用户取消年付续订时，latestSubscriptionInfo会变回月付产品ID，此时需将权限降级为月付级别。

3. 需补充的要点 #

• 状态优先级：存在多个订阅状态时，latestSubscriptionInfo代表用户当前的订阅意愿，优先级高于当前生效的交易。
• 跨设备同步：.subscriptionStatusTask会自动同步其他设备的订阅变更，逻辑需依赖StoreKit返回的状态，避免依赖本地缓存。
• 全场景测试：覆盖升级、降级、取消续订、账单重试期、宽限期等所有订阅状态，确保权限判断准确。
• 错误处理：当前代码中try?会忽略解析错误，实际开发中需添加错误捕获，避免因交易解析失败导致状态判断错误。

内容的提问来源于stack exchange，提问作者KatM