Android点击CardView跳转并加载Firebase对应分类数据问题求助

Hey Tomislav, let's get this click-to-category feature working! You're already halfway there with your Firestore RecyclerView setup—we just need to add click handling to your adapter and pass the right data to your new Activity. Here's how to do it step by step:

Step 1: Add Click Listener to Your RecyclerView Items #

First, we'll add an OnClickListener to each item in your FirmeAdapter's FirmeHolder. This lets us detect when a user taps a CardView (or item layout) and trigger the navigation.

Modify your FirmeHolder constructor like this:

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);

        // Add item click listener here
        itemView.setOnClickListener(v -> {
            // Get the position of the clicked item
            int position = getAdapterPosition();
            // Make sure we're not dealing with an invalid position
            if (position != RecyclerView.NO_POSITION) {
                // Fetch the corresponding Firme object for the clicked item
                Firme clickedCategory = getItem(position);
                // Create an Intent to navigate to your new Activity
                Intent intent = new Intent(itemView.getContext(), BeautyIzbornik.class);
                // Pass the category data (we'll use naziv as the identifier here)
                intent.putExtra("SELECTED_CATEGORY", clickedCategory.getNaziv());
                // Start the new Activity
                itemView.getContext().startActivity(intent);
            }
        });
    }

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

Step 2: Modify Your New Activity to Load Category-Specific Data #

Now, update your BeautyIzbornik Activity to receive the category data from the Intent, then query Firestore for all items under that category.

First, create an entity class for your items (let's call it Item) with fields matching your Firestore collection, then make an adapter (ItemAdapter) similar to your FirmeAdapter. Then implement the Activity:

public class BeautyIzbornik extends AppCompatActivity {
    private FirebaseFirestore db = FirebaseFirestore.getInstance();
    private CollectionReference itemsCollection = db.collection("your_items_collection"); // Replace with your actual items collection name
    private ItemAdapter itemAdapter;

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

        // Get the category name passed from MainActivity
        String selectedCategory = getIntent().getStringExtra("SELECTED_CATEGORY");

        // Set up RecyclerView with category-specific query
        setUpRecyclerView(selectedCategory);
    }

    private void setUpRecyclerView(String categoryName) {
        // Query Firestore for items where the category matches the selected one
        // Adjust the field name ("category") to match what's in your Firestore items
        Query categoryQuery = itemsCollection.whereEqualTo("category", categoryName)
                .orderBy("item_name", Query.Direction.ASCENDING);

        FirestoreRecyclerOptions<Item> options = new FirestoreRecyclerOptions.Builder<Item>()
                .setQuery(categoryQuery, Item.class)
                .build();

        itemAdapter = new ItemAdapter(options);

        RecyclerView recyclerView = findViewById(R.id.recycler_view_items); // Replace with your RecyclerView ID
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setAdapter(itemAdapter);
    }

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

    @Override
    protected void onStop() {
        super.onStop();
        itemAdapter.stopListening();
    }
}

Important Notes to Check #

• Register Your Activity: Make sure BeautyIzbornik is added to your AndroidManifest.xml (Android Studio usually does this automatically when you create the Activity, but double-check).
• Firestore Collection Structure: Ensure your items collection has a field (like category) that matches the naziv value from your kategorije collection—this is how we filter items by category.
• Item Entity & Adapter: Create the Item class and ItemAdapter just like your Firme and FirmeAdapter, but with fields that match your items in Firestore (e.g., item name, description, image URL, etc.).

That should do it! When you tap a CardView in MainActivity, it'll send the category name to BeautyIzbornik, which will load and display all items under that category.

内容的提问来源于stack exchange，提问作者Tomislav Jurišić