Instance Method


Called when the activation of a session finishes.



func session(_ session: WCSession, activationDidCompleteWith activationState: WCSessionActivationState, error: Error?)



The session object whose activation completed.


The state of the session. Sessions normally move to the WCSessionActivationState.activated state upon success or the WCSessionActivationState.notActivated state when there is an error. On iOS, the session may also move to the WCSessionActivationState.inactive state if there is data waiting to be delivered from a previous session.


An error object indicating that a problem occurred or nil if activation completed successfully. When the activationState parameter contains the value WCSessionActivationState.notActivated, this parameter contains the error object describing the reason for the failure.


You must implement this method to support asynchronous activation and quick watch switching. Your implementation should check the value of the activationState parameter to see if communication with the counterpart app is possible. When the state is WCSessionActivationState.activated, you may communicate normally with the other app.

See Also

Managing Session Activation

func sessionDidBecomeInactive(WCSession)

Called when the session prepares to stop communicating with the current Apple Watch.


func sessionDidDeactivate(WCSession)

Called after all data from the previous session has been delivered and communication with the Apple Watch has ended.