我RecyclerView用它從 Cloud FirestoreCardViews中檢索了兩個TextViews，每當我點擊卡片時，我希望它根據pdfUrl存儲在我的 Firestore 數據庫中，使用 pdf 打開活動或將 pdf 下載到手機。但我不知道如何實現這一目標。我的代碼：public class RecylerViewTestsActivity extends AppCompatActivity {RecyclerView recyclerView;private FirebaseFirestore db = FirebaseFirestore.getInstance();private FirestoreRecyclerAdapter<uploadTests, TestesViewHolder> adapter;@Overrideprotected void onCreate(@Nullable Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.recyler_view_tests);    RecyclerView recyclerView = findViewById(R.id.recyclerViewTests);    recyclerView.setLayoutManager(new LinearLayoutManager(this));    FirebaseFirestore rootRef = FirebaseFirestore.getInstance();    Query query = rootRef.collection("FilterPDFUploads");    FirestoreRecyclerOptions<uploadTests> options = new FirestoreRecyclerOptions.Builder<uploadTests>()            .setQuery(query, uploadTests.class)            .build();    adapter = new FirestoreRecyclerAdapter<uploadTests,TestesViewHolder >(options) {        @Override        protected void onBindViewHolder(@NonNull TestesViewHolder holder, int position, @NonNull uploadTests model) {            holder.setTestesDesc(model.getDescription());            holder.setTestesName(model.getUsername());        }        @NonNull        @Override        public TestesViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {            View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.pdf_tests_items, parent, false);            return new TestesViewHolder(view);        }    };    recyclerView.setAdapter(adapter);}//////////////////////////VIEW HOLDER////////////////////////////////////////////private class TestesViewHolder extends RecyclerView.ViewHolder {    private View view;    private CardView itemsCard;    TestesViewHolder(final View itemView) {        super(itemView);        view = itemView;    }