内购StoreKit->SKPaymentTransaction.h
typedef NS_ENUM(NSInteger, SKPaymentTransactionState) {
SKPaymentTransactionStatePurchasing,
SKPaymentTransactionStatePurchased,
SKPaymentTransactionStateFailed,
SKPaymentTransactionStateRestored,
SKPaymentTransactionStateDeferred,
};
@interface SKPaymentTransaction : NSObject {
@property(nonatomic, readonly, nullable) NSError *error;
@property(nonatomic, readonly, nullable) SKPaymentTransaction *originalTransaction;
@property(nonatomic, readonly) SKPayment *payment;
@property(nonatomic, readonly) NSArray<SKDownload *> *downloads;
@property(nonatomic, readonly, nullable) NSDate *transactionDate;
@property(nonatomic, readonly, nullable) NSString *transactionIdentifier;
@property(nonatomic, readonly, nullable) NSData *transactionReceipt;
@property(nonatomic, readonly) SKPaymentTransactionState transactionState;
@end