Question

我有一个活动与数据库连接并且我所有的数据都来了，但是我想当我单击一个Card视图以从数据卡中打开数据时。我喜欢第一页的类别，当我单击一个类别时，我想获取该类别中的所有项目。我仍在（独自）学习，这是我自己无法解决的第一个问题。请帮我。我已经尝试了所有可以在网上找到的东西。

    public class MainActivity extends AppCompatActivity  {

        ImageButton imageButton;

        private FirebaseFirestore db = FirebaseFirestore.getInstance();
        private CollectionReference firemRef = db.collection("kategorije");

        private FirmeAdapter adapter;


        @Override
        protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        setUpRecyclerView();






 }

          private void setUpRecyclerView(){
         Query query= firemRef.orderBy("logo",Query.Direction.DESCENDING);
         FirestoreRecyclerOptions<Firme> options = new 
         FirestoreRecyclerOptions.Builder<Firme>()
            .setQuery(query,Firme.class)
            .build();
         adapter= new FirmeAdapter(options);

          RecyclerView recyclerView = findViewById(R.id.recycler_view);
          recyclerView.setHasFixedSize(true);
          recyclerView.setLayoutManager(new LinearLayoutManager(this));
          recyclerView.setAdapter(adapter);
}



       @Override
       protected void onStart() {
       super.onStart();
       adapter.startListening();
}

       @Override
       protected void onStop() {
        super.onStop();
        adapter.stopListening();
}
        public void onClickButton (View view){

        Intent intent= new Intent(MainActivity.this,BeautyIzbornik.class);
        MainActivity.this.startActivity(intent);


}


}

我的适配器

    import com.firebase.ui.firestore.FirestoreRecyclerAdapter;
    import com.firebase.ui.firestore.FirestoreRecyclerOptions;
    import com.squareup.picasso.Picasso;

    public class FirmeAdapter extends  FirestoreRecyclerAdapter<Firme, FirmeAdapter.FirmeHolder> {






        /**
         * Create a new RecyclerView adapter that listens to a Firestore         Query.  See {@link
         * FirestoreRecyclerOptions} for configuration options.
         *
         * @param options
         */
        public FirmeAdapter(@NonNull FirestoreRecyclerOptions<Firme>         options) {

            super(options);
        }


        @Override
        protected void onBindViewHolder(@NonNull FirmeHolder holder, int         position, @NonNull final Firme model) {
            holder.naziv.setText(model.getNaziv());
            holder.setLogo(model.getLogo());


        }        

        @NonNull
        @Override
        public FirmeHolder onCreateViewHolder(@NonNull ViewGroup viewGroup,         int i) {
            View v =         LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.firme_item,
                    viewGroup,false);
            return new FirmeHolder(v);






        }


        class FirmeHolder extends RecyclerView.ViewHolder {
            ImageButton imageButton;
            TextView naziv;


            public FirmeHolder(@NonNull final View itemView) {
                super(itemView);
                naziv = itemView.findViewById(R.id.naziv);
                imageButton =itemView.findViewById(R.id.logo);



            }
            public void setLogo(String logo) {
                Picasso.get().load(logo).into(imageButton);
            }




        }        


    }

我的活动和数据

    public class Firme {

        public String logo;
        public String naziv;
        public String url;



        public Firme ( ) {

        }

        public Firme (String naziv, String logo , String url){
            this.logo= logo;
            this.naziv= naziv;
            this.url = url;
        }

        public String getLogo() {
            return logo;
        }

        public String getNaziv() {
            return naziv;
        }
        public void setLogo(String logo){
            this.logo = logo;
        }

        public String getUrl(){
            return url;
        }
        public void setUrl(String url){
            this.url=url;
        }
    }

Answer 1

您必须对RecyclerView项执行点击侦听器：由于每个项目都有自己的数据，因此您应该使用此数据显示足够的信息：如何为RecyclerView

实现点击监听器

在您的RecyclerView.Adapter中，只需创建一个可以使用的界面即可。

private onItemClickListener mItemClickListener;

public void setOnItemClickListener(onItemClickListener mItemClickListener) {
        this.mItemClickListener = mItemClickListener;
}

public interface onItemClickListener {
    void onItemClickListener(View view, int position, MyData myData);
}

在这种情况下，mItemClickListener是适配器内部的全局变量，并且这两种方法也都位于适配器内部。

然后在ViewHolder内部，使用itemView.setOnClickListener（this）（或您要单击以检索数据的任何组件）将click侦听器应用于itemView

@Override
public void onClick(View view) {
    if (mItemClickListener != null) {
        mItemClickListener.onItemClickListener(view, getAdapterPosition(), my_data.get(getAdapterPosition()));
    }
}

这将通过已单击的视图，该视图的位置以及该位置内列表中包含的对象。

因此，在“活动”中，您只需简单地调用界面即可。

adapter.setOnItemClickListener(new CustomAdapter.onItemItemClickListener() {
    @Override
    public void onItemClickListener(View view, int position, MyData data) {
    //do on item click functionality here
    }
});

我如何单击一个活动上的卡片视图并使用Firebase中的数据打开新活动

1 个答案: