RecyclerView仅在编辑要添加的下一个项目时显示该项目

Question

I'm currently building an activity in my app where products are added using a FAB. Clicking the FAB opens a new pop-up activity with startActivityForResult, and in it a form is filled and sent back via a Parcelable object.

The problem I'm facing right now is that after adding a product it is not displayed in the RecyclerView, but when I click the FAB again, the second I start editing any field inside the form (meaning any EditText, for example) for the next product, I see the previous one appearing in the background behind my pop-up form. When I finish the second product, it won't appear until I start editing the third one, etc.

I went through the XML and it seems OK to me... And tried reading several solutions (and my code again and again) but none of them were really helpful.

Relevant pieces of code (I put ... where I neglected some code that's irrelevant for this case): From the main activity (in it the products are meant to be shown):

'''

public class EditOffersActivity extends AppCompatActivity {
    ...
    private ArrayList<Offer> offers_list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_edit_products);
        offers_list = new ArrayList<>();

        ...

        RecyclerView rvOffers = findViewById(R.id.offers_RecyclerView);
        OfferAdapter adapter = new OfferAdapter(offers_list);
        rvOffers.setAdapter(adapter);
        rvOffers.setLayoutManager( new LinearLayoutManager(this));

        // Setting up the FAB so it leads to the Product Details Pop-up
        FloatingActionButton fab = findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(EditOffersActivity.this, ProductDetailsPopupActivity.class);
                startActivityForResult(intent, HTZ_ADD_OFFER); // HTZ_ADD_OFFER = 1
            }
        });
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        Offer created_offer = data.getParcelableExtra("offer");
        offers_list.add(created_offer);
    }
}

'''

The Adapter: '''

public class OfferAdapter extends android.support.v7.widget.RecyclerView.Adapter<OfferAdapter.OfferViewholder> {
    private ArrayList<Offer> mOffers;

    public OfferAdapter(ArrayList<Offer> offers) {
        mOffers = offers;
    }

    @Override
    public OfferViewholder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
        Context context = viewGroup.getContext();
        int layoutIdForListItem = R.layout.item_product;
        LayoutInflater inflater = LayoutInflater.from(context);

        View view = inflater.inflate(layoutIdForListItem, viewGroup, false);
        OfferViewholder viewHolder = new OfferViewholder(view);

        return viewHolder;
    }

    @Override
    public void onBindViewHolder(OfferViewholder holder, int position) {
        Offer current_offer = mOffers.get(position);
        ... // a lot of binding code
    }


    @Override
    public int getItemCount() {
        return mOffers.size();
    }

    class OfferViewholder extends RecyclerView.ViewHolder {
        TextView name_TextView;
        TextView time_TextView;
        ...

        public OfferViewholder(View itemView) {
            super(itemView);

            // Init all views
            name_TextView = itemView.findViewById(R.id.product_item_name_TextView);
            time_TextView = itemView.findViewById(R.id.product_item_time_TextView);
             ...

        }
    }
}

'''

And the bit from the popup activity that closes it after the user click 'finished': '''

mPublishButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(p_photo_url == null) {
                ...
                } else {

                    // Create offer from user input
                    Offer n_offer = new Offer   (...)
                    );

                    ...

                    // Return offer to EditOffersActivity
                    Intent resultIntent = new Intent();
                    resultIntent.putExtra("offer", n_offer); // Offer is Parcelable
                    setResult(HTZ_ADD_OFFER, resultIntent);
                    finish();
                }
            }
        });

'''

And the RecyclerView's XML:

<android.support.v7.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/offers_RecyclerView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:layoutManager="android.support.v7.widget.LinearLayoutManager"
    tools:itemCount="3"
    tools:listitem="@layout/item_product"
    tools:orientation="vertical"
    tools:scrollbars="horizontal"
    tools:spanCount="1">

Answer 1

you can use notifydatasetchanged as below code :

mPublishButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(p_photo_url == null) {
                ...
                } else {

                    // Create offer from user input
                    Offer n_offer = new Offer   (...)
                    );

                    ...

                    // Return offer to EditOffersActivity
                    Intent resultIntent = new Intent();
                    resultIntent.putExtra("offer", n_offer); // Offer is Parcelable
                    setResult(HTZ_ADD_OFFER, resultIntent);
                    OfferAdapter.notifydatasetchanged();
                    finish();
                }
            }
        });

OfferAdapter.notifydatasetchanged();// method will refresh the adapter which is set on your view. and the values will be refresh.

Don't forget to appreciate and like the answer.

Answer 2

Add a method on your adapter like this:

public void update(ArrayList<Offer> offers){
            mOffers = offers;
        }

Update your onActivityResult and notify adapter like this:

@Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        Offer created_offer = data.getParcelableExtra("offer");
        offers_list.add(created_offer);
        adpater.update(offers_list);
        adapter.notifydatasetchanged();
    }

Answer 3

after adding to ArrayList You Have to notify changes to Adaptor by calling RecyclerViewAdapter's notifydatasetchanged()

like:

adapter.notifydatasetchanged()