尝试在swift中为Class签名添加协议

Question

我正在尝试在swift中创建一个应用内购买.在我的班级签名中,我有以下内容:

class ViewController: UIViewController, UITextFieldDelegate, UIAlertViewDelegate,   
SKStoreProductViewControllerDelegate, SKPaymentTransactionObserver{

但是,我收到一条错误消息:类型"ViewController"不符合协议:SKPaymentTransactionObserver

我读过这个:https://developer.apple.com/library/prerelease/mac/documentation/Swift/Conceptual/BuildingCocoaApps/WritingSwiftClassesWithObjective-CBehavior.html并在ViewController中符合协议,在Swift中

SKSoreProductViewControllerDelegate工作正常.我错过了什么？

Answer 1

您是否在课堂上实施了所需的方法？

paymentQueue:updatedTransactions:并且paymentQueue:updatedDownloads:是必需的方法,如果没有实现,您将收到警告.

Answer 2

SKPaymentTransactionProtocol 有这些方法:

func paymentQueue(queue: SKPaymentQueue!, updatedTransactions transactions: [AnyObject]!) 
@optional func paymentQueue(queue: SKPaymentQueue!, removedTransactions transactions: [AnyObject]!)
@optional func paymentQueue(queue: SKPaymentQueue!, restoreCompletedTransactionsFailedWithError error: NSError!)
@optional func paymentQueueRestoreCompletedTransactionsFinished(queue: SKPaymentQueue!)
@optional func paymentQueue(queue: SKPaymentQueue!, updatedDownloads downloads: [AnyObject]!)

第一个是您的类必须实现的必需方法,以符合协议.将它添加到ViewController,错误将消失.

class ViewController: UIViewController, UITextFieldDelegate, UIAlertViewDelegate,   
SKStoreProductViewControllerDelegate, SKPaymentTransactionObserver{
    func paymentQueue(queue: SKPaymentQueue!, updatedTransactions transactions: [AnyObject]!){/*...*/}
    /*...*/
}