Callback invoked to process a message received on a CFMessagePort object.
- iOS 2.0+
- macOS 10.0+
- UIKit for Mac 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
- Core Foundation
The local message port that received the message.
An arbitrary integer value assigned to the message by the sender.
The message data.
infomember of the
CFMessagestructure that was used when creating
Data to send back to the sender of the message. The system releases the returned CFData object. Return
NULL if you want an empty reply returned to the sender.
If you want the message data to persist beyond this callback, you must explicitly create a copy of
data rather than merely retain it; the contents of
data will be deallocated after the callback exits.