Question

我的目标是通过回调从适配器激活Fragment的“ RefreshList（）”功能。
但是Fragment文档告诉我照片中的以下消息：我以为他要我发送回叫，但我不知道它是如何完成的，非常感谢您的帮助

我附上我的片段代码和适配器以防万一 AlertasFragment：

@Override
    public void FragmentMethod() {
        RefreshList();
    }

我使用的方法是：

public class Alerts_Adapter extends RecyclerView.Adapter<Alerts_Adapter.MyViewHolder> {
    private String idPet;
    private String TipoAnuncio;
    private Context mContext;
    private List<MyAdsCard> anunciosList;
    private StorageReference mStorageReference;
    private String idUser;
    //llamar funcion de fragment

    AdapterCallback callback;

    public interface AdapterCallback{
        void FragmentMethod();
    }



    ArrayList<String> ChatIdList;
    ArrayList<String> OtherUserIdList;


    public class MyViewHolder extends RecyclerView.ViewHolder {
        public TextView title, description, time;
        public ImageView thumbnail;
        public ImageButton btn_edit;
        public TextView et_typeAd;
        private TextView type_ad;
        private RelativeLayout type_adLayout;



        public MyViewHolder(View view) {
            super(view);
            title = (TextView) view.findViewById(R.id.title);
            description = (TextView) view.findViewById(R.id.description);
            time = (TextView) view.findViewById(R.id.time);
            thumbnail = (ImageView) view.findViewById(R.id.img);
            btn_edit = view.findViewById(R.id.btn_edit);
            et_typeAd = view.findViewById(R.id.et_typeAd);
            type_ad = (TextView) view.findViewById(R.id.et_typeAd);
            type_adLayout = view.findViewById(R.id.type_adLayout);

        }

    }


    public Alerts_Adapter(Context mContext, List<MyAdsCard> anunciosList, AdapterCallback callback) {
        this.mContext = mContext;
        this.anunciosList = anunciosList;
        this.callback = callback;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.myads_cardview, parent, false);

        ChatIdList = new ArrayList<String>();
        OtherUserIdList = new ArrayList<String>();


        return new MyViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(final MyViewHolder holder, int position) {

        //aquí carga los anuncios, los actualiza con bbdd, las imagenes
        final MyAdsCard anuncios = anunciosList.get(position);
        idPet=anuncios.getId();//coge id anuncio
        TipoAnuncio=anuncios.getTipoAnuncio();//coge tipo anuncio
        holder.title.setText(anuncios.getName());
        holder.description.setText(anuncios.getDescription());
        holder.time.setText(anuncios.getTime());
        if(anuncios.getTipoAnuncio().equals("Perdidos")) {
            holder.type_ad.setText("PERDIDO");
            holder.type_adLayout.setBackgroundResource(R.drawable.title_rounded_orange);
        }
        else if(anuncios.getTipoAnuncio().equals("Encontrados")){
            holder.type_ad.setText("ENCONTRADO");
            holder.type_adLayout.setBackgroundResource(R.drawable.title_rounded_green);
        }
        else if(anuncios.getTipoAnuncio().equals("Adopciones")){
            holder.type_ad.setText("ADOPCIÓN");
            holder.type_adLayout.setBackgroundResource(R.drawable.title_rounded_blue);

        }

        holder.thumbnail.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v) { //FER INTENT QUE PASSI EL ID PER DESPRES A LA FITXA IMPRIMIR LANUNCI AMB AQUEST ID I TIPO ANUNCIO
                //para hacer intent en el onclick
                TipoAnuncio=anuncios.getTipoAnuncio();
                idPet=anuncios.getId();
                Intent intent = new Intent (v.getContext(), DataPetActivity.class);
                intent.putExtra("TipoAnuncioFicha", TipoAnuncio);
                intent.putExtra("IdAnuncioFicha", idPet);
                mContext.startActivity(intent);

            }
        });
        holder.btn_edit.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v) {
                showPopupMenu(holder.btn_edit);
                //agafa dades, i actualitza su pica.
                TipoAnuncio=anuncios.getTipoAnuncio();
                idPet=anuncios.getId();

            }
        });

        //picasso agafa url i ho converteix amb imatge
        Picasso.get()
                .load(anuncios.getImg())
                .resize(200, 200)
                .centerCrop()
                .into(holder.thumbnail);
    }




    /**
     * Showing popup menu when tapping on 3 dots
     */
    private void showPopupMenu(View view) {
        // inflate menu
        PopupMenu popup = new PopupMenu(mContext, view);
        MenuInflater inflater = popup.getMenuInflater();
        inflater.inflate(R.menu.menu_alerts, popup.getMenu());
        popup.setOnMenuItemClickListener(new MyMenuItemClickListener());
        popup.show();
    }


    /**
     * Click listener for popup menu items
     */
    class MyMenuItemClickListener implements PopupMenu.OnMenuItemClickListener {

        public MyMenuItemClickListener() {
        }

        @SuppressLint("StringFormatMatches")
        @Override
        public boolean onMenuItemClick(MenuItem menuItem) {

            switch (menuItem.getItemId()) {
                /*
                case R.id.action_editAd:
                    Intent intent = new Intent (mContext, EditDataPetActivity.class);
                    intent.putExtra("TipoAnuncio", TipoAnuncio);
                    intent.putExtra("IdAnuncio", idPet);
                    ((MisAnunciosActivity) mContext).startActivityForResult(intent,1);
                    return true;*/
                case R.id.action_deleteAd:
                    showAlert(R.string.alert_title,String.format(mContext.getString(R.string.alert_delete)), idPet);

                    //deleteAlerts();
                    return true;
                default:

            }
            return false;
        }

    }

    private void showAlert(int title, String message, final String idRoom){
        android.support.v7.app.AlertDialog.Builder alertDialogBuilder =  new android.support.v7.app.AlertDialog.Builder(this.mContext,R.style.MyDialogTheme)
                .setTitle(title)
                .setMessage(message)
                .setPositiveButton(R.string.chat_alert_button_delete, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                        deleteAlerts();

                    }
                })
                .setNegativeButton(R.string.chat_alert_button_cancel, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });
        android.support.v7.app.AlertDialog alertDialog = alertDialogBuilder.create();
        alertDialog.show();
    }
    private void deleteAlerts() {
        DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
        String userId = FirebaseAuth.getInstance().getCurrentUser().getUid();
        DatabaseReference ref2 = rootRef.child("Usuarios").child(userId).child("Alerts").child(idPet);
        ref2.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                dataSnapshot.getRef().removeValue();
                Toast.makeText(mContext, "Alerta borrada.", Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });
        /*
//dir que refresqui llista myads SI FUNCIONA POSAR A MAPA I LLISTA QUAN ES CREA UN ANUNCI AMB ADDANUNCIO
        final AlertasFragment fragment = new AlertasFragment();
        fragment.RefreshList();
        //((AlertasFragment)mContext).RefreshList(); */
        //mCallBack.CallBackFragment();
        /*
        if(callback != null) {
            callback.FragmentMethod();
        }*/
        callback.FragmentMethod();
    }






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

Alerts_Adapter：

callback.FragmentMethod();

我用它来从片段中调用函数：

docRef.update({
  timestamp: firebase.firestore.FieldValue.serverTimestamp()
});

Answer 1

您可以为此编写一个接口回调。

互联网上有很多例子。

您问题的特定答案

请参阅此link

Answer 2

您可以传递当前的此对象，以实现您的callback，或者实现匿名类，或者使成为AdapterCallback的对象< / strong>，并按如下所示进行传递：

传递片段对象并实现它。

adapter = new Alerts_Adapter(getActivity(), myAdsObjectList, this);

或创建新的匿名对象。

adapter = new Alerts_Adapter(getActivity(), myAdsObjectList, new AdapterCallback { @Override public void FragmentMethod(){ // Here is your callback } });

或制作一个AdapterCallback的对象并像下面那样传递。

adapter = new Alerts_Adapter(getActivity(), myAdsObjectList, adapterCallback);

从适配器到片段的Android Studio回调

2 个答案: