One, general, purchase content includes content type, feature extension, service and subscription.
Second, the test environment to build:
Building a test environment is cumbersome and requires 2 tools to manage: The configuration portal for ITunes Connect and the iOS Dev Center.
Third, the data structure submitted to the App store can only be a Nsset collection, and the elements in the collection are product identification strings.
Four, Base64fordata, is to encode the NSData type of credential data Base64, using BASE64 encoding only if the text data is used to represent the binary.
Base64 is a representation of binary data based on 64 printable characters.
Why do I need Base64 encoding? Because the app Store can only receive BASE64 encoded data, where we encode it to the merchant's server, the merchant server does not need to be encoded. You can also encode on a merchant server.
Reference: "iOS network programming and cloud applications-best practices"
"Book notes" ios-in-app purchases