Question

当我单击心脏图标时，它将项目发送到收藏夹并更改颜色，但是在加载活动时，图标恢复正常颜色，但该商品仍在收藏夹中。

如何检查收藏夹中的项目是否更改图标颜色基于像带有数据库室的侦听器之类的东西？

这是适配器：-

    public class BSAdapter extends RecyclerView.Adapter<BSAdapter.BestSellerHolder> {
    private Context context;
    private List<ProductsBestSeller> bestSellerList;


    public BSAdapter(Context context, List<ProductsBestSeller> bestSellerList) {
        this.context = context;
        this.bestSellerList = bestSellerList;
    }

    @Override
    public BestSellerHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View bestSellerView = LayoutInflater.from(parent.getContext()).inflate(R.layout.default_product_items_horizontal, parent, false);
        return new BestSellerHolder(bestSellerView);
    }

    @Override
    public void onBindViewHolder(BestSellerHolder holder, int position) {
        ProductsBestSeller bestSeller = bestSellerList.get(position);
        holder.onBindData(bestSeller);

    }

    @Override
    public int getItemCount() {
        if (bestSellerList != null) {
            return bestSellerList.size();
        } else {
            return 0;
        }
    }

    public class BestSellerHolder extends RecyclerView.ViewHolder {

        TextView productName, productPrice;
        ImageView productIcon;
        CheckBox favouriteIcon;


        public BestSellerHolder(View itemView) {
            super(itemView);
            productIcon = itemView.findViewById(R.id.product_icon_horizontal);
            productName = itemView.findViewById(R.id.product_name_horizontal);
            productPrice = itemView.findViewById(R.id.product_price_horizontal);
            favouriteIcon = itemView.findViewById(R.id.favourite_icon_horizontal);
        }

        private void onBindData(ProductsBestSeller bestSeller) {
            if (Resources.getSystem().getConfiguration().locale.getLanguage().equals(Locale.ENGLISH.toString())) {
                productName.setText(bestSeller.getNameEn());
            } else {
                productName.setText(bestSeller.getNameAr());
            }
            Glide.with(context).load(bestSeller.getImage()).into(productIcon);
            productPrice.setText(String.valueOf(bestSeller.getPrice()));
            ProductsEntities entity = ProductsEntities.getEntityByBestSeller(bestSeller);
            if(entity.getFavourite() == 0){
                favouriteIcon.setButtonDrawable(R.drawable.ic_favorite_black_24dp);
            }else{
                favouriteIcon.setButtonDrawable(R.drawable.favourite_icon);
            }
            favouriteIcon.setOnCheckedChangeListener((buttonView, isChecked) -> {
                if (isChecked) {
                    favouriteIcon.setButtonDrawable(R.drawable.favourite_icon);
                    entity.setFavourite(1);
                    Repository.getRepository().addProductEntity(entity);
                    Toast.makeText(context, R.string.added_to_favourite, Toast.LENGTH_SHORT).show();
                } else {
                    favouriteIcon.setButtonDrawable(R.drawable.ic_favorite_black_24dp);
                    entity.setFavourite(0);
                    Repository.getRepository().addProductEntity(entity);
                    Toast.makeText(context, R.string.deleted_from_favourite, Toast.LENGTH_SHORT).show();

                }
            });
        }
    }
}

这是房间数据库Dao：-

@Dao
public interface MercDao {

    @Insert(onConflict = OnConflictStrategy.REPLACE)
    void addProduct(ProductsEntities entity);

    @Query("SELECT * FROM product_entity WHERE favourite_product == 1")
    LiveData<List<ProductsEntities>> getFavourites();

    @Query("SELECT * FROM product_entity WHERE cart_product == 1")
    LiveData<List<ProductsEntities>> getCart();

    @Query("UPDATE product_entity SET favourite_product = 1 WHERE product_id == :id")
    void setFavourite(String id);

    @Query("UPDATE product_entity SET cart_product = 1 WHERE product_id == :id")
    void setCart(String id);

    @Query("UPDATE product_entity SET cart_product = 0 WHERE product_id == :id")
    void deleteCart(String id);

    @Query("UPDATE product_entity SET favourite_product = 0 WHERE product_id == :id")
    void deleteFavourite(String id);
}

这是我的Room数据库实体：-

@Entity(tableName = "product_entity")
public class ProductsEntities {

    @PrimaryKey
    @NonNull
    @ColumnInfo(name = "product_id")
    private String id;
    @ColumnInfo(name = "product_name_en")
    private String nameEn;
    @ColumnInfo(name = "product_name_ar")
    private String nameAr;
    @ColumnInfo(name = "product_image")
    private String image;
    @ColumnInfo(name = "category_id")
    private String categoryId;
    @ColumnInfo(name = "store_id")
    private String storeId;
    @ColumnInfo(name = "product_price")
    private int price;
    // 1 for Recent ||  2 for BestSeller  ||  3 for CategoryProducts  ||  4 for StoreProducts
    @ColumnInfo(name = "product_type")
    private int product;

    @ColumnInfo(name = "favourite_product")
    private int favourite = 0;

    @ColumnInfo(name = "cart_product")
    private int cart = 0;

    public ProductsEntities() {

    }

    @NonNull
    public String getId() {
        return id;
    }

    public void setId(@NonNull String id) {
        this.id = id;
    }

    public String getNameEn() {
        return nameEn;
    }

    public void setNameEn(String nameEn) {
        this.nameEn = nameEn;
    }

    public String getNameAr() {
        return nameAr;
    }

    public void setNameAr(String nameAr) {
        this.nameAr = nameAr;
    }

    public String getImage() {
        return image;
    }

    public void setImage(String image) {
        this.image = image;
    }

    public String getCategoryId() {
        return categoryId;
    }

    public void setCategoryId(String categoryId) {
        this.categoryId = categoryId;
    }

    public String getStoreId() {
        return storeId;
    }

    public void setStoreId(String storeId) {
        this.storeId = storeId;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public int getProduct() {
        return product;
    }

    public void setProduct(int product) {
        this.product = product;
    }

    public int getFavourite() {
        return favourite;
    }

    public int getCart() {
        return cart;
    }

    public void setFavourite(int favourite) {
        this.favourite = favourite;
    }

    public void setCart(int cart) {
        this.cart = cart;
    }

click heart icon sends item to favorite

item in the favorite

when refreshing the fragment icon back to normal again

item still in the favorite

Answer 1

我在上面的代码中看到2个问题，

在我们添加和删除数据库时，您正在更新数据库，但是您如何处理本地视图引用是错误的。

原因：因为在您的情况下，不仅当您转到另一个屏幕后它都将不起作用，如果您滚动更多的东西（如果您有更多的项目再返回）也将不起作用，因为回收者视图会重用您的视图您在检查监听器中更新的内容，这导致了第二个问题
在onBindData中，您始终应使用非收藏夹图标，因此，每当滚动并查看重用时，它将仅显示非收藏夹图标，您应检查该项是否收藏夹，并应更新视图< / p>

例如，您应该像下面这样

override fun onBindViewHolder(holder: VM, position: Int) {
    val item = items.get(position)

    if (item.favourite == 0) {
        holder.name.text = item.name
    } else {
        holder.name.text = item.name + " Liked "
    }

    holder.favouriteIcon.setOnCheckedChangeListener { compoundButton, isChecked ->
        // Should not update local view reference here
        if(isChecked) {
            // Update the local reference object, Just not to update from DB
            item.favourite = 1
            // Do the logic to update the DB to add the item in Fav
        } else {
            // Update the local reference object, Just not to update from DB
            item.favourite = 0
            // Do the logic to update to remove the item from Fav list
        }
        notifyItemChanged(position) // Helps to update the particular item
    }
}

请根据您的项目修改代码。

将项目添加到收藏夹数据库时更改图标颜色

1 个答案: