堆棧內存溢出
  簡體   English   中英

我的 Recyclerview 有時顯示數據，有時不顯示

[英]My Recyclerview sometimes display data and sometimes it doesnt

 原文  2021-05-02 15:25:40  0   1    android/ android-recyclerview

問題描述

我的 Recyclerview 有時需要刷新才能開始顯示數據，有時需要很長時間才能顯示數據，有時它就像一個魅力。 我什至對 2 個回收站視圖使用了相同的適配器，其中一個立即顯示數據，但另一個完全沒有顯示，如下圖所示：

在此處輸入圖像描述

當我添加另一個回收器視圖但在使用相同適配器的不同片段中時，這個問題開始出現。 我認為使用相同的適配器是問題，所以我創建了一個新的，但問題仍然存在。 注意：我也使用相同的布局來顯示回收站視圖項目。 任何想法都會非常有幫助。 謝謝

更新：代碼

適配器：


import android.graphics.Paint
import android.view.LayoutInflater
import android.view.TextureView
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.DiffUtil
import androidx.recyclerview.widget.ListAdapter
import androidx.recyclerview.widget.RecyclerView
import com.bumptech.glide.Glide
import com.example.ecommapp.R
import com.example.ecommapp.main_activity.data.Product
import kotlinx.android.synthetic.main.product_item_layout.view.*

class ProductItemAdapter(val listener: ProductItemAdapter.onItemClickListener) : ListAdapter<Product, ProductItemAdapter.ProductViewHolder>(Comparator()) {


    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ProductViewHolder {
        val inflater = LayoutInflater.from(parent.context).inflate(R.layout.product_item_layout, parent, false)
        return ProductViewHolder(inflater)
    }

    override fun onBindViewHolder(holder: ProductViewHolder, position: Int) {
        val currentItem = getItem(position)
        if (currentItem != null) {
            holder.bind(currentItem)
        }
    }

    inner class ProductViewHolder(view : View): RecyclerView.ViewHolder(view){

        init {
            view.setOnClickListener{
                val position = adapterPosition
                val product = getItem(position)
                if(position != RecyclerView.NO_POSITION){
                    listener.onItemClick(product)
                }
            }

        }

        private val container = view.container_main

        private val imageView = view.img_product_item_not_card
        private val productName = view.tv_product_item_label
        private val productNewPrice = view.tv_product_item_new_price
        private val productOldPrice = view.tv_product_item_old_price

        fun bind(product: Product) {

            productName.text = product.title
            productNewPrice.text = product.price

            /*var temp = (product.price as Double ) * 1.5
            var oldPrice = temp as String

            productOldPrice.text = oldPrice
            productOldPrice.paintFlags = productOldPrice.paintFlags or Paint.STRIKE_THRU_TEXT_FLAG*/


            //Context of the view
            Glide.with(imageView.context) // Context
                .load(product.image) // Data
                .into(imageView) // View

        }

    }

    interface onItemClickListener{
        fun onItemClick(product : Product)
    }

    class Comparator : DiffUtil.ItemCallback<Product>() {
        override fun areItemsTheSame(oldItem: Product, newItem: Product) =
            oldItem.id == newItem.id

        override fun areContentsTheSame(oldItem: Product, newItem: Product) =
            oldItem == newItem
    }
}

查看 Model：


import android.content.ContentValues.TAG
import android.util.Log
import androidx.lifecycle.*
import com.example.ecommapp.main_activity.data.Product
import com.example.ecommapp.main_activity.retrofit.ProductsApi
import dagger.hilt.android.lifecycle.HiltViewModel
import dagger.hilt.android.scopes.ViewModelScoped
import kotlinx.coroutines.launch
import retrofit2.Call
import retrofit2.Callback
import retrofit2.Response
import javax.inject.Inject




@HiltViewModel
class HomeViewModel @Inject constructor(
    private val savedStateHandle: SavedStateHandle,
    val api : ProductsApi
) : ViewModel() {

    var new_collection_list : MutableLiveData<List<Product>>
    var best_sellling_list : MutableLiveData<List<Product>>

    init {
        new_collection_list = MutableLiveData()
        best_sellling_list = MutableLiveData()

        get_best_selling_data()
        get_new_collection_data()
    }

     fun get_new_collection_data(){

        var call = api.get_products_desc()
         call.enqueue(object : Callback<List<Product>> {
             override fun onResponse(call: Call<List<Product>>, response: Response<List<Product>>) {
                 if (response.body() != null){
                     new_collection_list.postValue(response.body())
                     Log.d(TAG, "onResponse: Success Response")
                 }

                 else{
                     new_collection_list.postValue(null)
                     Log.d(TAG, "onResponse: Null Response")
                }
             }

             override fun onFailure(call: Call<List<Product>>, t: Throwable) {
                 Log.d(TAG, "onFailure: Failure Response")
             }
         })
    }
     fun get_best_selling_data() {

         var call = api.get_products_asc()
         call.enqueue(object : Callback<List<Product>> {
             override fun onResponse(call: Call<List<Product>>, response: Response<List<Product>>) {

                 if (response.body() != null){
                     best_sellling_list.postValue(response.body())
                     Log.d(TAG, "onResponse: Success Response")
                 }
                 else{
                     best_sellling_list.postValue(null)
                     Log.d(TAG, "onResponse: Null Response")
                 }
             }

             override fun onFailure(call: Call<List<Product>>, t: Throwable) {
                 Log.d(TAG, "onFailure: Failure Response")
             }
         })
    }


    fun on_swipe_refresh(){
        get_new_collection_data()
        get_best_selling_data()
    }
}

分段：

package com.example.ecommapp.main_activity.fragments.home_fragment

import android.content.Context
import android.net.ConnectivityManager
import android.net.NetworkCapabilities
import android.os.Build
import android.os.Bundle
import android.os.Handler
import android.view.View
import android.widget.Toast
import androidx.fragment.app.Fragment
import androidx.fragment.app.viewModels
import androidx.lifecycle.LiveData
import androidx.lifecycle.Observer
import androidx.navigation.fragment.findNavController
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
import com.example.ecommapp.R
import com.example.ecommapp.main_activity.data.Product
import com.example.ecommapp.main_activity.shared_files.recycler_view_adapters.ProductItemAdapter
import dagger.hilt.android.AndroidEntryPoint
import kotlinx.android.synthetic.main.home_fragment_layout.*


@AndroidEntryPoint
class HomeFragment: Fragment(R.layout.home_fragment_layout), ProductItemAdapter.onItemClickListener {


    lateinit var new_collection_list : LiveData<List<Product>>
    lateinit var best_selling_list : LiveData<List<Product>>

    val new_collections_adapter = ProductItemAdapter(this)
    val best_selling_adapter = ProductItemAdapter(this)

    val viewModel : HomeViewModel by viewModels()

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)


        // New Collection Recycler View Setup
        rv_new_collections.layoutManager = LinearLayoutManager(
            activity?.applicationContext,
            LinearLayoutManager.HORIZONTAL,
            false
        )


        rv_new_collections.adapter = new_collections_adapter


        // Best Selling Recycler View Setup
        rv_best_selling.layoutManager = LinearLayoutManager(
            activity?.applicationContext,
            LinearLayoutManager.HORIZONTAL,
            false
        )


        rv_best_selling.adapter = best_selling_adapter

        //
        set_data()


        Handler().postDelayed({

            if ( isConnected(activity?.applicationContext) ){

                layout_new_collection_shimmer.visibility = View.INVISIBLE
                rv_new_collections.visibility = View.VISIBLE


                layout_best_selling_shimmer.visibility = View.INVISIBLE
                rv_best_selling.visibility = View.VISIBLE

                set_data()
            }
            else{
                Toast.makeText(activity?.applicationContext, "No Internet Connection, Swipe to reload.", Toast.LENGTH_LONG )
                    .show()
            }


        }, 2000)


        container_swipe.setOnRefreshListener(object : SwipeRefreshLayout.OnRefreshListener {
            override fun onRefresh() {

                if ( isConnected(activity?.applicationContext) ){

                    if( layout_new_collection_shimmer.visibility == View.INVISIBLE){

                        layout_new_collection_shimmer.visibility = View.INVISIBLE
                        rv_new_collections.visibility = View.VISIBLE


                        layout_best_selling_shimmer.visibility = View.INVISIBLE
                        rv_best_selling.visibility = View.VISIBLE
                    }


                    viewModel.on_swipe_refresh()
                    set_data()
                }
                else{
                    Toast.makeText(activity?.applicationContext, "No Internet Connection, Swipe to reload.", Toast.LENGTH_LONG )
                        .show()
                }



                // Must be added
                container_swipe.isRefreshing = false
            }


        })


    }

    fun set_data(){
        new_collection_list = viewModel.new_collection_list
        best_selling_list = viewModel.best_sellling_list

        new_collection_list.observe(viewLifecycleOwner, Observer {

            new_collections_adapter.submitList(it)
            new_collections_adapter.notifyDataSetChanged()
        })

        best_selling_list.observe(viewLifecycleOwner, Observer {
            best_selling_adapter.submitList(it)
            best_selling_adapter.notifyDataSetChanged()
        })
    }

    fun isConnected(ctx: Context?): Boolean {

        val hasInternet: Boolean

        val connectivityManager =
            ctx?.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            val networkCapabilities = connectivityManager.activeNetwork ?: return false
            val actNw =
                connectivityManager.getNetworkCapabilities(networkCapabilities) ?: return false
            hasInternet = when {
                actNw.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) -> true
                actNw.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) -> true
                actNw.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET) -> true
                else -> false
            }
        } else {
            hasInternet = try {
                if (connectivityManager.activeNetworkInfo == null) {
                    false
                } else {
                    connectivityManager.activeNetworkInfo?.isConnected!!
                }
            } catch (e: Exception) {
                false
            }
        }
        return hasInternet}

    override fun onItemClick(product : Product) {
        val action = HomeFragmentDirections.actionHomeFragmentToProductFragment(product, product.title, R.id.homeFragment)
        findNavController().navigate(action)
    }


}

布局：

<?xml version="1.0" encoding="utf-8"?>
<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
    android:id="@+id/container_swipe"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context=".main_activity.fragments.home_fragment.HomeFragment"
    >

    <ScrollView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        >
        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <androidx.appcompat.widget.SearchView
                android:id="@+id/search_view"
                android:layout_width="0dp"
                android:layout_height="50dp"

                app:layout_constraintWidth_percent="0.9"

                android:elevation="2dp"
                android:outlineProvider="bounds"

                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                android:layout_marginTop="20dp"/>


            <androidx.cardview.widget.CardView
                android:id="@+id/img_advertisment"
                android:layout_width="0dp"
                android:layout_height="180dp"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@id/search_view"

                app:layout_constraintWidth_percent="0.9"
                android:background="#00000000"
                app:cardElevation="0dp"
                app:cardCornerRadius="10dp"
                >

                <ImageView
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:src="@drawable/advertisment"
                    />

            </androidx.cardview.widget.CardView>

            <RelativeLayout
                android:id="@+id/container_new_collection"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                app:layout_constraintTop_toBottomOf="@id/img_advertisment"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintWidth_percent="0.9"
                android:layout_marginTop="20dp"
                >

                <TextView
                    android:id="@+id/tv_new_collection"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="New Collections"
                    android:textColor="@color/tomato"
                    android:textSize="25dp"
                    android:fontFamily="sans-serif-black"
                    android:layout_alignParentTop="true"
                    android:layout_alignParentLeft="true"/>

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Show All"
                    android:textSize="20dp"
                    android:textColor="#c6c4ce"
                    android:fontFamily="sans-serif-black"
                    android:layout_alignParentRight="true"
                    android:layout_alignParentTop="true"
                    android:layout_marginTop="5dp"/>

                <com.facebook.shimmer.ShimmerFrameLayout
                    android:id="@+id/layout_new_collection_shimmer"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    app:shimmer_repeat_mode="restart"
                    app:shimmer_shape="linear"
                    android:layout_below="@id/tv_new_collection"
                    android:layout_marginTop="10dp">

                    <HorizontalScrollView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        >
                        <LinearLayout
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:orientation="horizontal">

                            <include layout="@layout/product_shimmer_layout"></include>

                            <include layout="@layout/product_shimmer_layout"></include>

                            <include layout="@layout/product_shimmer_layout"></include>

                            <include layout="@layout/product_shimmer_layout"></include>

                            <include layout="@layout/product_shimmer_layout"></include>

                            <include layout="@layout/product_shimmer_layout"></include>
                        </LinearLayout>

                    </HorizontalScrollView>
                </com.facebook.shimmer.ShimmerFrameLayout>

                <androidx.recyclerview.widget.RecyclerView
                    android:layout_marginTop="10dp"
                    android:id="@+id/rv_new_collections"
                    android:layout_width="wrap_content"
                    android:layout_height="350dp"
                    android:layout_below="@id/tv_new_collection"
                    tools:listitem="@layout/product_item_layout"
                    android:visibility="invisible"
                    />

            </RelativeLayout>

            <RelativeLayout
                android:id="@+id/container_best_selling"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                app:layout_constraintTop_toBottomOf="@id/container_new_collection"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintWidth_percent="0.9"
                android:layout_marginTop="20dp"
                >

                <TextView
                    android:id="@+id/tv_best_selling"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Best Selling"
                    android:textColor="@color/tomato"
                    android:textSize="25dp"
                    android:fontFamily="sans-serif-black"
                    android:layout_alignParentTop="true"
                    android:layout_alignParentLeft="true"/>

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Show All"
                    android:textSize="20dp"
                    android:textColor="#c6c4ce"
                    android:fontFamily="sans-serif-black"
                    android:layout_alignParentRight="true"
                    android:layout_alignParentTop="true"
                    android:layout_marginTop="5dp"
                    />

                <com.facebook.shimmer.ShimmerFrameLayout
                    android:id="@+id/layout_best_selling_shimmer"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    app:shimmer_repeat_mode="restart"
                    app:shimmer_shape="linear"
                    android:layout_marginTop="10dp"
                    android:layout_below="@id/tv_best_selling">

                    <HorizontalScrollView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content">
                        <LinearLayout
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:orientation="horizontal">

                            <include layout="@layout/product_shimmer_layout"></include>

                            <include layout="@layout/product_shimmer_layout"></include>

                            <include layout="@layout/product_shimmer_layout"></include>

                            <include layout="@layout/product_shimmer_layout"></include>

                            <include layout="@layout/product_shimmer_layout"></include>

                            <include layout="@layout/product_shimmer_layout"></include>
                        </LinearLayout>

                    </HorizontalScrollView>

                </com.facebook.shimmer.ShimmerFrameLayout>

                <androidx.recyclerview.widget.RecyclerView
                    android:id="@+id/rv_best_selling"
                    android:layout_width="wrap_content"
                    android:layout_height="350dp"
                    android:layout_below="@id/tv_best_selling"
                    tools:listitem="@layout/product_item_layout"
                    android:layout_marginTop="10dp"
                    android:visibility="invisible"
                    />

            </RelativeLayout>

        </androidx.constraintlayout.widget.ConstraintLayout>
    </ScrollView>






</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>

1 個解決方案

解決方案1
 0  2021-05-02 20:59:06

我弄清楚是什么問題。 API 需要很長時間來發送數據。 因此，回收器視圖使用 null 值呈現視圖。

暫無
暫無

聲明:本站的技術帖子網頁，遵循CC BY-SA 4.0協議，如果您需要轉載，請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.

相關問題 Recyclerview有時顯示“null”，有時是我的數據 recyclerview有時會滾動獲取數據，有時不會 我的RecyclerView不更新（有時） firebase data recyclerview 有時什么都不顯示 為什么有時不調用我的 RecyclerView.ViewHolder 的 onClick 方法？ 有時包含數據，有時不包含數據的 Arraylist 為什么UI有時無法通過數據綁定在recyclerview中更新？ Android-FirebaseUI有時不顯示RecyclerView RecyclerView 有時無法加載 RecyclerView findViewHolderForAdapterPosition 有時會返回 null
相關標簽
 
粵ICP備18138465號  © 2020-2024 STACKOOM.COM