A protocol that provides updates for the discovery and management of peripheral devices.


@protocol CBCentralManagerDelegate


The CBCentralManagerDelegate protocol defines the methods that a delegate of a CBCentralManager object must adopt. The optional methods of the protocol allow the delegate to monitor the discovery, connectivity, and retrieval of peripheral devices. The only required method is centralManagerDidUpdateState:; the central manager calls this when its state updates, thereby indicating the availability of the central manager.


Monitoring Connections with Peripherals

- centralManager:didConnectPeripheral:

Tells the delegate that the central manager connected to a peripheral.

- centralManager:didDisconnectPeripheral:error:

Tells the delegate that the central manager disconnected from a peripheral.

- centralManager:didFailToConnectPeripheral:error:

Tells the delegate the central manager failed to create a connection with a peripheral.

- centralManager:connectionEventDidOccur:forPeripheral:

Tells the delegate that a connection event occurred which matches the registered options.

Discovering and Retrieving Peripherals

- centralManager:didDiscoverPeripheral:advertisementData:RSSI:

Tells the delegate the central manager discovered a peripheral while scanning for devices.

Advertisement Data Retrieval Keys

Keys used to specify items in a dictionary of peripheral advertisement data.

Monitoring the Central Manager’s State

- centralManagerDidUpdateState:

Tells the delegate the central manager’s state updated.


- centralManager:willRestoreState:

Tells the delegate the system is about to restore the central manager, as part of relaunching the app into the background.

Monitoring the Central Manager’s Authorization

- centralManager:didUpdateANCSAuthorizationForPeripheral:

Tells the delegate the authorization status changed for a ANCS-requiring connected peripheral.


Inherits From

See Also



A remote device connected to a local app, which is acting as a peripheral.


An object that scans for, discovers, connects to, and manages peripherals.