看了下Storekit 2 ，解决了1的很多问题，如Product的的信息扩充，测试状态下的退订状态。 而且使用上async，aawait的swift新特性，api，使用方法都很简单明了。就是对版本的要求现在来说还是有点高15.0
let result = try await product.purchase(options: [uuid])
// demo
func purchase(_ product: Product) async throws -> Transaction? {
//Begin a purchase.
let result = try await product.purchase()
switch result {
case .success(let verification):
let transaction = try checkVerified(verification)
//Deliver content to the user.
await updatePurchasedIdentifiers(transaction)
//Always finish a transaction.
await transaction.finish()
return transaction
case .userCancelled, .pending:
return nil
default:
return nil
}
}
