WatchConnectivity provides two-way communication between a paired iPhone app and its companion Apple Watch app. You activate a WCSession and assign a WCSessionDelegate to observe the session's WCSessionActivationState and to receive incoming data, then send live messages, queue background user-info updates through WCSessionUserInfoTransfer, and move files between devices using WCSessionFileTransfer and WCSessionFile. Errors surface as WCError, letting you handle failed transfers and unreachable counterparts.
Essentials 3
Establish and observe the communication session that connects a paired iPhone and Apple Watch app.
- ClWCSessioniOS 9.0+-------------------------------- WCSession --------------------------------
- PrWCSessionDelegate----------------------------- WCSessionDelegate -----------------------------
- EnWCSessionActivationStateiOS 9.3+Constants that indicate whether a session is inactive, activated, or not yet activated.
Transferring Files 2
Move files between the paired devices and track each transfer in progress.
- ClWCSessionFileTransferiOS 9.0+Used to track a file being transferred.
- ClWCSessionFileiOS 9.0+Contains file information, such as the file's location and optional user info
Transferring User Info 1
Queue background dictionaries that are delivered to the counterpart app even when it isn't running.
- ClWCSessionUserInfoTransferiOS 9.0+Used to track a user info dictionary being transferred.
Handling Errors 1
Identify and respond to failures that occur during communication or transfers.
- StWCErroriOS 9.0+A structure that describes errors arising from session activation, message delivery, or transfer failures.