swift - 从闭包中调用 "fulfill"时出错

Question

这是我的错误...

Thread 1: EXC_BAD_ACCESS (code=1, address=0x18)

这是我的产品请求代表...

class ProductRequestDelegate : NSObject, SKProductsRequestDelegate {

    private var products: ([SKProduct]) -> Void

    init(products: @escaping ([SKProduct]) -> Void) {

        self.products = products
    }

    public func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {

        products(response.products)
    }

    public func request(_ request: SKRequest, didFailWithError error: Error) {

    }
}

这是请求...

fileprivate var productsRequest: SKProductsRequest?

public func getProducts() -> Promise<Set<SKProduct>> {

        return Promise { fulfill, reject in

            productsRequest?.cancel()

            productsRequest = SKProductsRequest(productIdentifiers: productIdentifiers)

            productsRequest!.delegate = ProductRequestDelegate { products in

                self.productsRequest = nil

                fulfill(Set(products))
            }

            productsRequest!.start()
        }
    }

此调用会导致错误发生...

_ = iAPHelper.getProducts()

有什么想法为什么这不起作用？看来委托(delegate)已被释放。

Answer 1

SKProductsRequest 上的委托(delegate)属性是unowned(unsafe)，因此分配给它的对象被释放。 (仪器在打开僵尸后通知我释放。)

因此，我向包含函数 getProducts() 的类添加了对委托(delegate)的引用。并且它有效。