Question

Alright, i have read many different views on how to do this with no success. Maybe i am missing something or not doing something right, so any help i appreciate…

So, i have 2 Classes. Lets say Class A is an activity and has a public method called classAmethod();

Now, Class B actually extends a BroadcastReceiver. So in Class B i need to start classAmethod();

—

So far when i try this, it will want to make it static. But i cant do that. I have tried some other methods that dont make it static but for some reason it automatically wants it to be static and if something isn’t it will FC once the method is called.

Answer 1

There are a number of ways you can do this so I’ll just outline 2 ways I would do this.

Option 1. use a listener

create an interface

public interface Listener {

public abstract void onEvent();

}

in the broadcast receiver create a static reference and setter

private static MessageListener mListener = null;

@Override
public void onReceive(Context context, Intent intent) {
    //stuff
        if(mListener != null)
             mListener.onEvent();   
}

public static void setListener(Listener l) {
    mListener = l;
}

then implement the listener in the Activity

class MyActivity implements Listener{

    @Override
    public void onResume(){
        //register the listener, should probably unregister in onDestroy
        BroadCastReceiver.setListener(this);
    }

    @Override
    public void onEvent(){
        //do something
    }
}

Option 2. use an intent

In the broadcast receiver

Intent intent = new Intent();
Bundle bundleToSend = new Bundle(); 
//BUNDLE_EXTRA,DO_SOME_ACTION and ACTION_KEY are just constants so just define them somewhere
bundleToSend.putInt(ACTION_KEY, DO_SOME_ACTION);        
intent.putExtra(BUNDLE_EXTRA, bundleToSend);
intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
startActivity(intent);

The flag FLAG_ACTIVITY_SINGLE_TOP will start the activity if its not started or if it is running it will be caught in onNewIntent() so you will need to put some code in both the onCreate() and onNewIntent() to extract the bundle and check for the action.

final Bundle bundleReceived = intent.getBundleExtra(BUNDLE_EXTRA);
if (bundleReceived.getInt(ACTION_KEY) == DO_SOME_ACTION) {
    //do something
}

Option 1 is really only useful for when the broadcast receiver is only going to be receiving when the activity is at the forefront. Option 2 is more versatile and can be used even when the app is not running (eg the broadcast receiver is run in a service started on boot) so that the activity will be started and the action performed no matter the state of the activity.