How to pass data from BroadcastReceiver to Activity without in onCreate()

Question

I have a serious issue about passing data from BroadcastReceiver to an Activity. Let see my issue carefully. I have a class PhoneStateReceiver ex

Answer 1

There is a very simple design pattern you can use here to ease communication between your classes and also decouple your code: publisher/subscriber. My favorite library for this is EventBus:

First, add to your build.gradle file:

compile 'org.greenrobot:eventbus:3.0.0'

Then, create a simple POJO - Plain Old Java Object like this:

public class OnReceiverEvent{
   private String phoneNumber;

   public OnReceiverEvent(String phone){
      this.phoneNumber = phone;
   }

   public String getPhoneNumber(){
      return phoneNumber;
   }
}

Next, by making your Receiver class a publisher, and your Activity a subscriber, you should be able to easily pass the information to your activity like this:

//inside your PhoneStateReceiver class when you want to pass info

EventBus.getDefault().post(new OnReceiverEvent(phoneNumber));

Next, inside your activity, simply do this:

//onStart
@Override
public void onStart(){
   super.onStart();
   EventBus.getDefault().register(this);
}

//onStop
@Override
public void onStop(){
   super.onStop();

   EventBus.getDefault().unregister(this);
}

Finally, handle the posted data i.e phoneNumber value:

@Subscribe
public void onPhoneNumberReceived(OnReceiverEvent event){
   //get the phone number value here and do something with it

   String phoneNumber = event.getPhoneNumber();

   //display or something?
}

UPDATE

If you have another Event that you want this activity to subscribe to, simply create a method like you did in the first one using the @Subscribe annotation.

@Subscribe
public void onSomeOtherEvent(EventClassName event){
   //get the variables here as usual;
}

This is the easiest way to pass the data from your receiver to your activity without having to worry about starting the activity over and over!

I hope this helps and good luck!