[Solved]Error : IAP Button in Google Play return duplicate Transaction error

unity version : 2017.2.0.f3
unity iap version: 1.20.1

i used iap Button in my game, like this :

and the code in ShopManager.cs like this

Code (CSharp):

1.     public void OnSuccessfullyBuy1000Coins(Product product)
2.     {
3.         Data.inst.jimServer.AddMoney(1000);
4.         InfoText.SetText("Successfully Buy 1000 Coins");
5.         InfoText.transform.parent.parent.gameObject.SetActive(true);
6.     }
7.     public void OnFaildBuy1000Coins(Product product, PurchaseFailureReason purchaseFailureReason)
8.     {
9.         Debug.Log(purchaseFailureReason.ToString());
10.         InfoText.SetText(purchaseFailureReason.ToString());
11.         InfoText.transform.parent.parent.gameObject.SetActive(true);
12.     }

so after the first purchase will successfully load the google play UI, but the

OnSuccessfullyBuy1000Coins()

seems not calling after i finished the payment, and from the second purchase on this same product, it will keep calling the

OnFaildBuy1000Coins() 

with

PurchaseFailureReason.DuplicateTransaction

does anybody have the same issue?

 

Ok, turns out that Google Play need a couple of day to make the the IAP functional. i finally getting OnSuccessfullyBuy1000Coins() call now