在SKPaymentTransaction中进行交易时发生投放问题（Swift 3）

Question

I am trying to get to the error code in a transaction (Swift 3):

func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
        for transaction in transactions {
            if let errorCode = (transaction.error as NSError).code {
             //Do something
            }
        }


}

I am getting the below error.

'Error?' is not convertible to 'NSError'; did you mean to use 'as!' to force downcast?`.

Why wont this work? I thought Error could cast to NSError in Swift 3.

Answer 1

Try to cast the Error object to NSError then access error code.

if let nsError = error as? NSError {
    print(nsError.code)
}