使用 SwiftUI 进行条带化

Question

我正在尝试使用 STPApplePayContextDelegate 在我的 SwiftUI 应用中实现 Stripe。

我根据这个documentation 创建了一个符合这个委托的类，但没有运气。我收到此错误：// Type of expression is ambiguous without more context 在这一行 let applePayContext = STPApplePayContext(paymentRequest: paymentRequest, delegate: self)

我在这里做错了什么？

struct PaymentButtonController : UIViewControllerRepresentable {
    
    class Coordinator : NSObject, STPApplePayContextDelegate {
        var vc : UIViewController?
        
        @objc func buttonPressed() {
            let merchantIdentifier = "merchant.com.your_app_name"
            let paymentRequest = StripeAPI.paymentRequest(withMerchantIdentifier: merchantIdentifier, country: "US", currency: "USD")

            // Configure the line items on the payment request
            paymentRequest.paymentSummaryItems = [
                // The final line should represent your company;
                // it'll be prepended with the word "Pay" (i.e. "Pay iHats, Inc $50")
                PKPaymentSummaryItem(label: "iHats, Inc", amount: 50.00),
            ]
            
            // Initialize an STPApplePayContext instance
                if let applePayContext = STPApplePayContext(paymentRequest: paymentRequest, delegate: self) {
                    // Present Apple Pay payment sheet
                    if let vc = vc {
                        applePayContext.presentApplePay(on: vc)
                    }
                    
                } else {
                    // There is a problem with your Apple Pay configuration
                }
        }
        
        func applePayContext(_ context: STPApplePayContext, didCreatePaymentMethod paymentMethod: STPPaymentMethod, paymentInformation: PKPayment, completion: @escaping STPIntentClientSecretCompletionBlock) {
            let clientSecret = "..."
            print("ENDLICH")
            // Retrieve the PaymentIntent client secret from your backend (see Server-side step above)
            // Call the completion block with the client secret or an error
            completion(clientSecret, nil);
        }
        
        func applePayContext(_ context: STPApplePayContext, didCompleteWith status: STPPaymentStatus, error: Error?) {
            print("ENDLICH")
            switch status {
            case .success:
                // Payment succeeded, show a receipt view
                break
            case .error:
                // Payment failed, show the error
                break
            case .userCancellation:
                // User cancelled the payment
                break
            @unknown default:
                fatalError()
            }
        }
    }
    
    func makeCoordinator() -> Coordinator {
        return Coordinator()
    }
    
    func makeUIViewController(context: Context) -> UIViewController {
        let button = PKPaymentButton(paymentButtonType: .plain, paymentButtonStyle: .automatic)
        button.addTarget(context.coordinator, action: #selector(context.coordinator.buttonPressed), for: .touchUpInside)
        let vc = UIViewController()
        context.coordinator.vc = vc
        vc.view.addSubview(button)
        return vc
    }
    
    func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
        
    }
}

Answer 1

您正在调用的函数 (presentApplePay) 需要 UIViewController 作为其输入，但您传递的是 self，即您的 ApplePayContext，上面定义为 NSObject, ObservableObject, STPApplePayContextDelegate。

您将面临的挑战是将UIViewController 上下文传递给它，因为在纯 SwiftUI 中您不会有任何对 UIViewController 的引用。

您有几个可能的解决方案：

1. 在您的 SceneDelegate 中，将 UIHostingController 的引用传递给您的视图，然后将其用作presentApplePay 的参数
2. 使用 UIViewControllerRepresentable 获取 UIViewController，您可以将其嵌入到您的 SwiftUI 视图中并作为参数传递 (https://developer.apple.com/documentation/swiftui/uiviewcontrollerrepresentable)
3. 使用 SwiftUI-Introspect 之类的库将底层 UIViewController 获取到当前的 SwiftUI 视图 (https://github.com/siteline/SwiftUI-Introspect)

更新： 为了响应您对代码的请求，请从这里开始。请注意，并非所有内容都已连接 - 您需要连接 buttonPressed 方法，向按钮添加布局约束等，但它为您提供了一种方法来确定如何获取对 UIViewController 的引用

struct PaymentButtonController : UIViewControllerRepresentable {
    
    class Coordinator : NSObject {
        var vc : UIViewController?
        
        @objc func buttonPressed() {
            print("Button with VC: \(vc)")
        }
    }
    
    func makeCoordinator() -> Coordinator {
        return Coordinator()
    }
    
    func makeUIViewController(context: Context) -> UIViewController {
        let button = PKPaymentButton()
        button.addTarget(context.coordinator, action: #selector(context.coordinator.buttonPressed), for: .touchUpInside)
        let vc = UIViewController()
        context.coordinator.vc = vc
        vc.view.addSubview(button)
        return vc
    }
    
    func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
        
    }
}

在您的 SwiftUI 代码中使用它嵌入到您的视图中：

PaymentButtonController()