Called when a data transfer operation finished successfully or because of an error.
- iOS 9.0+
- Mac Catalyst 13.0+
- watchOS 2.0+
The session object of the current process.
An object containing information about the data that was transferred.
An error object if a problem occurred.
The session object calls this method when a data transfer initiated by the current app finished, either successfully or unsuccessfully. Use this method to note that the transfer completed or to respond to errors, perhaps by trying to send the data again at a later time.
This method is called on a background thread of your app.