当库存数为 0 时，Recyclerview 项目显示空白

Question

当我从响应中得到库存计数为 0 时，产品未显示，但产品位置在 grid recycler view kotlin 中显示空白。我将整个列表传递给适配器，然后按存货数量对其进行过滤。如果库存数量为 0，则该产品不会显示，但在应用程序中会显示该产品的空位

class ProductListAdapter(
    val productlists: List<Data>,
    val context: Context,
    val addCart: AddCartListener
) : RecyclerView.Adapter<ProductListAdapter.ProductListViewHolder>() {

    private val TAG = "ProductListAdapter"

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ProductListViewHolder {
        var itemView =
            LayoutInflater.from(parent.context).inflate(R.layout.product_list, parent, false)
        return ProductListViewHolder(itemView)
    }

    override fun onBindViewHolder(holder: ProductListViewHolder, position: Int) {

        val product: Data = productlists[position]
        val variantslist: List<Variant> = product.variants
        holder.setIsRecyclable(false)

        holder.productname.text = product.name

        Glide.with(holder.itemView.context)
            .load(product.image)
            .into(holder.productimage)

        Log.e(TAG, "onBindViewHolder: " + product.variants[0].cart_count)

        if (variantslist.get(0).cart_count == 0) {
            holder.btn_addcart.visibility = View.VISIBLE
            holder.ll_cart.visibility = View.GONE
        } else {
            holder.btn_addcart.visibility = View.GONE
            holder.ll_cart.visibility = View.VISIBLE
            holder.tv_cart.text = variantslist.get(0).cart_count.toString()
        }

        holder.btn_addcart.setOnClickListener {
            variantslist.get(0).cart_count = variantslist.get(0).cart_count + 1
            addCart.addCart(variantslist.get(0))
            notifyDataSetChanged()
        }

        holder.tv_addcart.setOnClickListener {
            variantslist.get(0).cart_count = variantslist.get(0).cart_count + 1
            addCart.addCart(variantslist.get(0))
            notifyDataSetChanged()
        }

        holder.tv_removecart.setOnClickListener {
            variantslist.get(0).cart_count = variantslist.get(0).cart_count - 1
            addCart.addCart(variantslist.get(0))
            notifyDataSetChanged()
        }

        if (variantslist[0].stock.toInt() > 0) {
            holder.mrp.text = "₹" + "%.2f".format(variantslist[0].price.toDouble())
            holder.mrp.paintFlags = Paint.STRIKE_THRU_TEXT_FLAG
            holder.discountprice.text =
                "₹" + "%.2f".format(variantslist[0].discounted_price.toDouble())

            if (variantslist[0].measurement_unit_name == null) {
                holder.singlevariant.text = variantslist[0].measurement + " pcs"
                holder.multivariant.text = variantslist[0].measurement + " pcs"
            } else {
                holder.singlevariant.text =
                    variantslist[0].measurement + variantslist[0].measurement_unit_name
                holder.multivariant.text =
                    variantslist[0].measurement + variantslist[0].measurement_unit_name
            }
        } else {
            holder.singlevariant.visibility = View.GONE
            holder.multivariant.visibility = View.GONE
            holder.mrp.visibility = View.GONE
            holder.discountprice.visibility = View.GONE
            holder.productCardView.visibility = View.GONE
            holder.ProductConstraint.visibility = View.GONE
            holder.productimage.visibility = View.GONE
            holder.productname.visibility = View.GONE
            holder.btn_addcart.visibility = View.GONE
            holder.ll_cart.visibility = View.GONE
            holder.tv_addcart.visibility = View.GONE
            holder.tv_removecart.visibility = View.GONE
            holder.tv_cart.visibility = View.GONE
            holder.pricediff.visibility = View.GONE
            holder.pricedifference.visibility = View.GONE
        }

        var diffvalue =
            ((variantslist[0].price.toDouble() - variantslist[0].discounted_price.toDouble()))
        var percentage = (diffvalue / variantslist[0].price.toDouble()) * 100
        if (percentage > 3) {
            holder.pricediff.visibility = View.VISIBLE
            holder.pricedifference.visibility = View.VISIBLE
            holder.pricediff.text = percentage.toInt().toString() + "% \nOff"
        } else {
            holder.pricediff.visibility = View.GONE
            holder.pricedifference.visibility = View.GONE
        }

        if (variantslist.size > 1) {
            holder.multivariant.visibility = View.VISIBLE
            holder.singlevariant.visibility = View.GONE
            holder.multivariant.setOnClickListener {
                //need to show dropown
                showCustomDialog(product)
            }
        } else {
            //navigate product details page
            holder.singlevariant.visibility = View.VISIBLE
            holder.multivariant.visibility = View.GONE
        }

        holder.itemView.setOnClickListener {
            movefrag(product)
        }
    }

    open fun getUserId(): String? {
        val preferences = context.getSharedPreferences(
            "userInfo",
            Activity.MODE_PRIVATE
        ) //Frequent to get SharedPreferences need to add a step getActivity () method
        return preferences.getString("customer_id", "90336")
    }

    fun movefrag(product: Data) {
        addCart.navFragment(product)
    }

    fun showCustomDialog(product: Data) {

        val dialog = Dialog(context)
        dialog.requestWindowFeature(Window.FEATURE_NO_TITLE)
        dialog.setCancelable(false)
        dialog.setContentView(R.layout.dialog_listview)
        val btndialog: Button = dialog.findViewById(R.id.btndialog) as Button
        btndialog.setOnClickListener { dialog.dismiss() }

        val listView: ListView = dialog.findViewById(R.id.listview) as ListView
        val adapter = VariantAdapter(context, product, addCart)
        listView.adapter = adapter
        listView.setOnItemClickListener(AdapterView.OnItemClickListener { parent, view, position, id ->
            Log.e(TAG, "showCustomDialog: " + adapter.getItem(position))
            dialog.dismiss()
        })
        dialog.setCanceledOnTouchOutside(true)
        dialog.show()
    }

    override fun getItemCount(): Int {
        return productlists.size
    }

    class ProductListViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {

        var productimage: ImageView
        var productname: TextView
        var mrp: TextView
        var discountprice: TextView
        var btn_addcart: TextView
        var ll_cart: LinearLayout
        var tv_addcart: TextView
        var tv_removecart: TextView
        var tv_cart: TextView
        var multivariant: TextView
        var singlevariant: TextView
        var pricediff: TextView
        var pricedifference: ImageView
        var productCardView: CardView
        var ProductConstraint: ConstraintLayout

        init {
            productimage = itemView.productimage
            productname = itemView.productname
            mrp = itemView.mrp
            discountprice = itemView.Discountprice
            btn_addcart = itemView.btn_addcart
            ll_cart = itemView.ll_cart
            tv_addcart = itemView.tv_addcart
            tv_removecart = itemView.tv_removecart
            tv_cart = itemView.tv_cart
            multivariant = itemView.multivariant
            singlevariant = itemView.singlevariant
            pricediff = itemView.pricediff
            pricedifference = itemView.pricedifference
            productCardView = itemView.productcardview
            ProductConstraint = itemView.productconstraint
        }
    }
}

This is the image of Best Sellers , i should not get that empty between items

这是片段代码

private fun getpopular() {

    LoadingUtils.showDialog(context, false)

    username = getUserId()

    val retrofitBuilder = Retrofit.Builder()
        .addConverterFactory(GsonConverterFactory.create())
        .baseUrl(BASE_L)
        .build()
        .create(ApiInterface::class.java)

    val retrofitData = retrofitBuilder.getpopularproductitems(90336, username!!)

    retrofitData.enqueue(object : Callback<productlist> {

        override fun onResponse(call: Call<productlist>, response: Response<productlist>) {
            Log.e("latest", "res-" + response.body())
            val responsebody: productlist = response.body()!!
            LoadingUtils.hideDialog()
            popularadapter = popularproductAdapter(frag, responsebody.data, addCart)
            popularadapter.notifyDataSetChanged()
            linearLayoutManager = LinearLayoutManager(context)
            popularproductsRView.adapter = popularadapter
        }

        override fun onFailure(call: Call<productlist>, t: Throwable) {
            Log.d("MainError", "onFailure: " + t.message)
            LoadingUtils.hideDialog()
        }
    })
}

Answer 1

我正在考虑 productlist class 如下：

data class productlist(val uid: Int, val data: List<BasicTimer>,...)

而你的Dataclass如下：

data class Data(val uid: Int, var stock_count: Int,...)

首先更改 productlist class 中变量 data 的名称，因为它是 Kotlin 的关键字。

现在在 retrofitData.enqueue() 过滤列表中确实有 stock_count > 0

替换以下行：

popularadapter = popularproductAdapter(frag, responsebody.data, addCart)

与：

popularadapter = popularproductAdapter(frag, responsebody.data.filter{it.stock_count > 0}, addCart)

这不会将带有 stock_count = 0 的对象发送到要渲染的 RecyclerView。

更好的选择是将 ViewModel 与 RecyclerView 一起使用，这样您就可以观察数据在初始运行之后是否发生了变化。

当库存数为 0 时，Recyclerview 项目显示空白

Recyclerview item shows empty spaces when stock count is 0

adapter

android-fragments

kotlin

android-studio

android-recyclerview