iPhone Store Kit “Cannot connect to iTunes Store”

When develop the IAP feature follow with the Apple IAP guide , I get a failed case:

- (void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transactions

case SKPaymentTransactionStateFailed

with this error:
error Error Domain=SKErrorDomain Code=0 "Cannot connect to iTunes Store" UserInfo=0x1e0edb60 {NSLocalizedDescription=Cannot connect to iTunes Store}

after lots of search, I found the solution in stackoverflow:

引用

had a similar issue, was getting "Cannot connect to iTunes Store" with Code=0. This is how I solved it, after trying every other ritualistic piece of advice found on the Internet from re-downloading my certificates to resetting all my device settings to sacrificing a virgin black goat:

In the target summary for the app, I used to have my version number in the "build" field, but nothing in "version" field. This seemed odd to me, so I moved the version number from "build" to "version". This resulted in the aforementioned error. Moving the version number back to "build" solved the error.