在委托方法中添加完成处理程序
问题描述:
我很难理解完成处理程序。我试图让一个函数(purchaseRequest)等待,直到另一个函数(didReceiveResponse)不被我调用,而是作为委托完成。有人能给我一个关于如何实现这一目标的指针吗?在委托方法中添加完成处理程序
func productsRequest(request: SKProductsRequest, didReceiveResponse response: SKProductsResponse) {
print("response received")
if response.products.count != 0 {
productsArray = response.products[0]
print(productsArray)
} else { print("No Products Found") }
}
func purchaseRequest() {
requestProductInfo()
//NEED TO HOLD UNTIL didReceiveResponse (which, as a delegate method, is not called by me) IS DONE.
print("Product1: \(self.productsArray)")
let aSC = UIAlertController(title: "Premium App Required", message: "Premium App is Required for this feature. Would you like to purchase it for $0.99?", preferredStyle: UIAlertControllerStyle.ActionSheet)
let buyAction = UIAlertAction(title: "Purchase", style: UIAlertActionStyle.Default) { (action) -> Void in
let payment = SKPayment(product: self.productsArray)
SKPaymentQueue.defaultQueue().addPayment(payment)
}
let cancelAction = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel) { (action) -> Void in
}
aSC.addAction(buyAction)
aSC.addAction(cancelAction)
self.presentViewController(aSC, animated: true, completion: nil)
}
答
•推进度微调视图控制器
•使purchaseRequest
后立即返回requestProductInfo()
•requestProductInfo()
后的委托方法捕获代码的新方法
•,dispatch_async()
到主队列并调用新方法
•在新方法中,弹出微调视图控制器,然后进行高级购买舞蹈
谢谢!我所做的是调用requestProductInfo(),然后使用dispatch_async()在didReceiveResponse委托内部进行purchaseRequest! –
@JacoboKoenig太棒了!小心“一路阻挡”陷阱;回调处理程序调用异步方法传递回调处理程序,该回调处理程序使用回调处理程序调用另一个方法。 (我充满罪责)。在某个时候,您想要将回调处理程序重构为自己的方法,然后调用它。 – bbum