Binding services

1. Binding to services from activities

If the activity wants to interact with the service directly, it can use the bindService() method to start the service.

This method requires a ServiceConnection object as a parameter which is called on the service start and when finishing its onBind() method. This method returns a IBinder object to the ServiceConnection.

This IBinder object can be used by the activity to communicate with the service.

When the binding process has finished, the onStartCommand() method in the service is called with the Intent object used for the bindService() method.

2. Local services bindings

If the service runs in the same process as the activity, it is possible to return the service to the activity. This allows that the activity can call methods of the service directly. This technique is demonstrated by <xref linkend="exercise_bindlocalservice" />.

3. Interprocess communication services bindings

If the service run in its own process, you require IPC (Interprocess Communication) to communicate with the service.