How to pass values from a Class to Activity - Android

Question

I have a newbie question about Class/Task/Activity. I\'m coming from C so I don\'t know if it\'s a good approach to do what I need.

I\'ve created a class:

Answer 1

You have an A activity and B one, when you finish actions on B activity side you need it to effect A side when you come back.

1. Create an Instance Class and a method that u type u need, let's say;

   public interface SelectedBirthday {
   
       void onSelectedData(String date);
   }
   

2. Now we are on B side, Create an instance of your Interface Class

   private SelectedBirthday mCallback;
   

3. Override

   @Override
   public void onAttach(Activity activity) {
       super.onAttach(activity);
   
       try {
           mCallback = (SelectedBirthday) activity;
       } catch (ClassCastException e) {
           Log.d("MyDialog", "Activity doesn't implement the ISelectedData interface");
       }
   }
   

4. Now upload the value you needed

   String userBirth = (day + " " + month + " " + year);
   
   mCallback.onSelectedData(userBirth);
   

5. Ok let's go to A side

Implement our Interface Class

implements SelectedBirthday

it will warn you for its method and you implemented it

     @Override
        public void onSelectedData(String date) {
            if (!date.equals("")) {
                txt_poup_age.setText(date);
//now you are free to do what you want with the value you received automaticaly
            }
        }