Service call backs to activity in android

android, callback, service

Solution

Here is the flow Create your intent to call a service. You can either `startService()` or `BindService()` with `BIND_AUTO_CREATE`

Once the service is bond, it will create a tunnel to talk with it clients which is the `IBinder` Interface. This is used by your AIDL Interface implementation and return the `IBinder` in

private final MyServiceInterface.Stub mBinder = new MyServiceInterface.Stub() {
    public int getNumber() {
        return new Random().nextInt(100);
    }
};

public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    Toast.makeText(this, "Service OnBind()", Toast.LENGTH_LONG).show();
    return mBinder;
}

Once it returns the `mBinder`, `ServiceConnection` that you created in the client will be called back and you will get the service interface by using this

           mConnection = new ServiceConnection() {

        public void onServiceDisconnected(ComponentName name) {
            // TODO Auto-generated method stub

        }

        public void onServiceConnected(ComponentName name, IBinder service) {
            // TODO Auto-generated method stub

            mService = MyServiceInterface.Stub.asInterface(service);


    };

Now you got the `mService` interface to call and retreive any service from that

Problem

I have a background service running and a client which interacts with the service. When the client requests for some operation, the service performs it and it should send the result back to the activity (client). I know how to invoke the service methods in activity and using call backs we can achieve what I want to do. But I am not able to understand the call back mechanism and code example provided in Api demos (remoteservice). Could someone explain how this service callback works; or anything which is achievable using simpler mechanism.

Original source