如何将带有其他对象数组的对象从一个片段传递到另一个片段？

Question

I have one object, let's call it Shop , and this object has an array of objects called Offers . How should I use Bundle with my object to send it from a 1st Fragment to the one I open with a onClickListener ?

Beeing Shop , the object I need to parse something like:

public class Shop {

    private String name;
    private String schedule;
    private String direction;
    private List<Offer> Offers = new ArrayList<Offer>();
}

and Offer Something like :

public class Offer {

    private int packsAvailable;
    private String description;
}

and that function calls the second fragment:

public void onClick(View v) {


    Fragment shopping = new OffersDisplayFragment();

    //Instantiate fragment
    FragmentTransaction fragmentTransaction = 
    activity.getSupportFragmentManager()
        .beginTransaction();
    fragmentTransaction.replace(R.id.fragment, shopping);
    fragmentTransaction.addToBackStack(null);
    fragmentTransaction.commit();
}

Answer 1

You can achieve it by adding a method to create an Instance of the next Fragment (I assume it is the OffersDisplayFragment).

Add the following method to your fragment so we can create Fragment with bundle:

public class OffersDisplayFragment extends Fragment {
    public static final String SHOP_EXTRA = "shopExtra";

    // Creates a new fragment given a Shop
    public static OffersDisplayFragment newInstance(Shop shop) {
        OffersDisplayFragment fragment = new OffersDisplayFragment();
        Bundle args = new Bundle();
        args.putSerializable(SHOP_EXTRA, shop);
        fragment.setArguments(args);
        return fragment;
    }
}

Then update or create onCreate method of your fragment to handle the bundle:

public class OffersDisplayFragment extends Fragment {
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       // Get back arguments
       Shop = (Shop) getArguments().getSerializable(SHOP_EXTRA);

       // Do something with the Shop here   
   }
}

in this point, Android Studio will complaining that your Shop model can't be serialized. This is expected, because we haven't declare the Shop as serializable . So, change your Shop and Offer as serializable like this:

public class Shop implements Serializable {
  ...
}

and

public class Offer implements Serializable {
  ...
}

Now, you can create the fragment with the bundle in your click listener like this:

public void onClick(View v) {

    Fragment shoppingFragment = OffersDisplayFragment.newInstance(shop);

    ...
    // show the fragment with the fragment transaction.
}

---

After you have a working solution, try using Parcelable instead Serializable .