我想从 Firebase 获取产品 ID

Question

我正在从 Firebase 检索产品信息，但问题是我无法选择存储在 Firebase 中的任何特定 ID。

我尝试了不同的解决方案来解决这个问题，get(position)但它正在获取产品在 RecyclerView 中的位置

这是 ProductsAdapteronBindViewHolder函数。

使用 * 添加更改

    @Override

    public void onBindViewHolder(@NonNull ProductViewHolder holder, int position) {

        Product productCurrent = mProducts.get(position);

        holder.product_title.setText(toCapitalize(productCurrent.getpTitle()));

        holder.product_pice.setText("$: " + productCurrent.getpPrice());

        Picasso.with(mContext)

                .load(productCurrent.getpImageUrl())

                .placeholder(R.mipmap.ic_launcher)

                .fit()

                .centerCrop()

                .into(holder.product_image);

        holder.parentLayout.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                Intent intent = new Intent(mContext, ProductPreview.class);

                intent.putExtra("pImageUrl", productCurrent.getpImageUrl());

                intent.putExtra("pTitle", toCapitalize(productCurrent.getpTitle()));

                intent.putExtra("pPrice", productCurrent.getpPrice());

                intent.putExtra("pDescription", toCapitalize(productCurrent.getpDescription()));

                Toast.makeText(mContext, " " + position, Toast.LENGTH_SHORT).show();

                mContext.startActivity(intent);

            }

        });

    }

此代码来自 ProductsActivity 具有RecyclerView

    private ProductsAdapter mAdapter;

    private ProgressBar mProgressBar;

    DatabaseReference mDatabaseReference;

    private ArrayList<Product> mProducts;

    ***ArrayList<ProductKeys> mProductKeys;***

Answer 1

如果您尝试在position方法中确定项目的 Firebase 数据库 ID onBindViewHolder，则必须自己维护该映射。您可以通过从快照中提取getKey()和并保留它们的列表来轻松地做到这一点。getValue()onDataChange是这样的：mProductKeys = new ArrayList<String>();mDatabaseReference.addValueEventListener(new ValueEventListener() {&nbsp; &nbsp; @Override&nbsp; &nbsp; public void onDataChange(@NonNull DataSnapshot dataSnapshot) {&nbsp; &nbsp; &nbsp; &nbsp; for (DataSnapshot postSnapShot : dataSnapshot.getChildren())&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Product product = postSnapShot.getValue(Product.class);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; mProducts.add(product);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; mProductKeys.add(postSnapShot.getKey());&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; mAdapter = new ProductsAdapter(ProductsActivity.this, mProducts);&nbsp; &nbsp; &nbsp; &nbsp; mRecyclerView.setAdapter(mAdapter);&nbsp; &nbsp; &nbsp; &nbsp; mProgressBar.setVisibility(View.INVISIBLE);&nbsp; &nbsp; }然后在 中，onBindViewHolder您可以查找在 中单击的项目的键mProductKeys。

Answer 2

好的，我尝试了不同的方法，只需添加一行即可完成。:) 无需添加ArrayList<String>。    @Override    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {        for (DataSnapshot postSnapShot : dataSnapshot.getChildren())        {            Product product = postSnapShot.getValue(Product.class);            product.setpKey(postSnapShot.getKey());            mProducts.add(product);        }        mAdapter = new ProductsAdapter(ProductsActivity.this, mProducts);        mRecyclerView.setAdapter(mAdapter);        mProgressBar.setVisibility(View.INVISIBLE);    }并添加String pKey到我的Product.classwith Setter and Getter。