Question

当我调用此方法时，在我的Xamarin应用程序中

private void MakePayment (SKProduct product)
{
    SKPayment payment = SKPayment.PaymentWithProduct (product);
    SKPaymentQueue.DefaultQueue.AddPayment (payment);
}

我收到此错误：

无法编组Objective-C对象0x14607110（类型： SKPaymentTransaction）。找不到现有的托管实例这个对象，也不可能创建一个新的托管实例（因为类型'MonoTouch.StoreKit.SKPaymentTransaction []'没有有一个构造函数，它接受一个IntPtr参数。）

我不确定我的配置是否有错或我的代码或Xamarin中存在问题。

这是Observer的代码

internal class CustomPaymentObserver : SKPaymentTransactionObserver
{
    private InAppPurchase inAppPurchase;

    public CustomPaymentObserver (InAppPurchase inAppPurchase)
    {
        this.inAppPurchase = inAppPurchase;
    }

    public override void UpdatedTransactions (SKPaymentQueue queue, SKPaymentTransaction[] transactions)
    {
        Console.WriteLine ("UpdatedTransactions");
        foreach (SKPaymentTransaction transaction in transactions) {
            switch (transaction.TransactionState) {
            case SKPaymentTransactionState.Purchased:
                inAppPurchase.CompleteTransaction (transaction);
                break;
            case SKPaymentTransactionState.Failed:
                inAppPurchase.FailedTransaction (transaction);
                break;
            default:
                break;
            }
        }
    }

    public override void PaymentQueueRestoreCompletedTransactionsFinished (SKPaymentQueue queue)
    {
    }

    public override void RestoreCompletedTransactionsFailedWithError (SKPaymentQueue queue, NSError error)
    {
    }
}

这是完整的堆栈跟踪：

System.Exception: Failed to marshal the Objective-C object 0x17ecb680 (type: SKPaymentTransaction). Could not find an existing managed instance for this object, nor was it possible to create a new managed instance (because the type 'MonoTouch.StoreKit.SKPaymentTransaction[]' does not have a constructor that takes one IntPtr argument).
at MonoTouch.ObjCRuntime.Runtime.MissingCtor (IntPtr ptr, IntPtr klass, System.Type type, MissingCtorResolution resolution) [0x00046] in /Developer/MonoTouch/Source/monotouch/src/ObjCRuntime/.pp-Runtime.cs:352
at MonoTouch.ObjCRuntime.Runtime.ConstructNSObject[NSObject] (IntPtr ptr, System.Type type, MissingCtorResolution missingCtorResolution) [0x00000] in :0
at MonoTouch.ObjCRuntime.Runtime.GetNSObject (IntPtr ptr, System.Type target_type, MissingCtorResolution missingCtorResolution, System.Boolean& created) [0x00073] in /Developer/MonoTouch/Source/monotouch/src/ObjCRuntime/.pp-Runtime.cs:514
at MonoTouch.ObjCRuntime.Runtime.GetNSObjectWrapped (IntPtr ptr, IntPtr type_ptr, System.Boolean& created) [0x0000c] in /Developer/MonoTouch/Source/monotouch/src/ObjCRuntime/.pp-Runtime.cs:686
at at (wrapper native-to-managed) MonoTouch.ObjCRuntime.Runtime:GetNSObjectWrapped (intptr,intptr,int&)
at at (wrapper managed-to-native) MonoTouch.ObjCRuntime.Messaging:void_objc_msgSend_IntPtr (intptr,intptr,intptr)
at MonoTouch.StoreKit.SKPaymentQueue.AddPayment (MonoTouch.StoreKit.SKPayment payment) [0x00014] in /Developer/MonoTouch/Source/monotouch/src/StoreKit/.pp-SKPaymentQueue.g.cs:109
at IOS.Util.IAP.InAppPurchase.ReceivedResponse (MonoTouch.StoreKit.SKProductsRequest request, MonoTouch.StoreKit.SKProductsResponse response) [0x0001d] in /Users/aaron/Projects/budget-ease-xamarin/IOS/Util/IAP/InAppPurchase.cs:43
at at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication:UIApplicationMain (int,string[],intptr,intptr)
at MonoTouch.UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0004c] in /Developer/MonoTouch/Source/monotouch/src/UIKit/.pp-UIApplication.cs:38
at IOS.Application.Main (System.String[] args) [0x00008] in /Users/aaron/Projects/budget-ease-xamarin/IOS/Main.cs:16

Answer 1

这里发生的事情是你的CustomPaymentObserver的C＃实例被垃圾收集，而它的本地（“Objective-C”）对应物仍然存在。当最终传递通知时，本机对象试图调用现在死亡的C＃对象并使应用程序崩溃。

要避免这种情况，请保留对CustomPaymentObserver的引用，例如在你的AppDelegate中保持活着。

我不确定Xamarin.iOS的某处是否有记录（快速找不到的东西），但我认为Xamarin.Droid非常相似（例如http://developer.xamarin.com/guides/android/advanced_topics/garbage_collection/）

Answer 2

我不确定是什么导致了这一点。我认为这可能与链接器有关。但是我完全从我的Mac上卸载了Xamarin（包括所有的MonoTouch东西）并重新安装了所有东西，现在它正在工作。

Xamarin SKPaymentQueue AddPayment抛出异常

2 个答案: