UnsetObserver() { SKPaymentQueue.DefaultQueue.RemoveTransactionObserver(paymentObserver); paymentObserver.TransactionStatusChanged -= OnTransactionStatusChanged; paymentObserver = null; }
SetObserver() { paymentObserver = new CustomPaymentObserver(); SKPaymentQueue.DefaultQueue.AddTransactionObserver(paymentObserver); paymentObserver.TransactionStatusChanged += OnTransactionStatusChanged; }