Making changes to Main Activity UI from thread in Service

I've been looking for quite some time for some good documentation or a good example of this. I need to make changes to my main activity UI from the worker thread in my service which is running in the background. As far as I understand I know that I am suppose to work with some sort of Handler but I am not sure exactly how to approach this.

Does anyone have any ideas or good examples that they could direct me to? The UI element I am changing is a TextView that 开发者_运维问答is simply informing the user of the status of the thread.

Thanks for your help.

All you have to do is to create a Handler on the UI thread:

private Handler serviceHandler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        someFunctionInTheUIThread();
    }
};

And then pass this through to your service. You could have a function in the Service like this:

public void registerHandler(Handler serviceHandler) {
    handler = serviceHandler;
}

and then pass the handler through like this:

theService = ((LocalBinder) service).getService();
theService.registerHandler(serviceHandler);

then to send a message back:

Message msg = handler.obtainMessage(IDENTIFIER, "Message or data");
handler.sendMessage(msg);

Look into Service Binding. Or you could use BroadcastReceiver in your main activity to receive broadcasts from Service.

You have to send an intent from your service with sendBroadcast(intent) and set a BroadcastReceiver in your activity

Create a handler in onCreate() method in your main activity. This will create a handler in the UI thread. Then using this handler from the worker thread, call whatever you need to to get the TextView updated.