Recyclerview 视图未正确显示列表项

Question

Screenshot of the recyclerview 我希望图像视图宽度与父级匹配，但我无法理解哪里出了问题？我已经将该基本元素设置为匹配父元素，然后添加约束以匹配父元素，但是在运行上，列表项不受限于 parent.Any 帮助的代码会有所帮助。

回收站视图：

<?xml version="1.0" encoding="utf-8"?>
<layout>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".favourites.FavouritesFragment">

    <androidx.recyclerview.widget.RecyclerView
        android:layout_margin="16dp"
        android:id="@+id/fav_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#C1D1E1"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        tools:listitem="@layout/memes_list_item" />

</LinearLayout>
</layout>

列表项布局：

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools">

 <data>

    <variable
        name="memes"
        type="com.example.mememvvm.database.MemesEntity" />
</data>


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

    <com.google.android.material.card.MaterialCardView
        android:id="@+id/card_view"
        android:layout_width="0dp"
        android:layout_height="350dp"
        android:layout_margin="16dp"
        android:padding="8dp"
        app:cardCornerRadius="10dp"
        app:cardElevation="10dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <ImageView
            android:id="@+id/meme_image_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:adjustViewBounds="false"
            android:padding="8dp"
            android:scaleType="centerInside"
            app:imageUrl="@{memes.url}"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"

            tools:src="@tools:sample/backgrounds/scenic" />
    </com.google.android.material.card.MaterialCardView>


    <com.google.android.material.textview.MaterialTextView
        android:id="@+id/recycler_view_like_text_view"
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:layout_gravity="center"
        android:layout_marginTop="16dp"
        android:drawablePadding="8dp"
        android:fontFamily="@font/acme"
        android:gravity="center"
        android:padding="8dp"
        android:text="@{Integer.toString(memes.ups)}"
        android:textColor="@color/black"
        android:textSize="20sp"
        android:textStyle="italic"
        app:drawableStartCompat="@drawable/ic_thumb_up"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/card_view"
        tools:text="999" />

</androidx.constraintlayout.widget.ConstraintLayout>

</layout>

适配器：

class FavouritesAdapter() :
ListAdapter<MemesEntity, FavouritesAdapter.FavouritesViewHolder>(DiffCallBack) {

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): FavouritesViewHolder {
    return 
FavouritesViewHolder(MemesListItemBinding.inflate(LayoutInflater.from(parent.context)))
}

override fun onBindViewHolder(holder: FavouritesViewHolder, position: Int) {
    val memes = getItem(position)
    holder.bind(memes)
}

companion object DiffCallBack : DiffUtil.ItemCallback<MemesEntity>() {
    override fun areItemsTheSame(oldItem: MemesEntity, newItem: MemesEntity): Boolean {
        return oldItem == newItem
    }

    override fun areContentsTheSame(oldItem: MemesEntity, newItem: MemesEntity): Boolean {
        return oldItem.url == newItem.url
    }

}

class FavouritesViewHolder(private var binding: MemesListItemBinding) :
    RecyclerView.ViewHolder(binding.root) {
    fun bind(memes: MemesEntity) {
        //binding.recyclerViewLikeTextView.text = memes.ups.toString()
        //Glide.with()
        binding.memes = memes
        binding.executePendingBindings()
    }
}

}

调用函数代码： class FavouritesFragment : 片段() {

private lateinit var binding: FragmentFavouritesBinding
private lateinit var viewModel: FavouritesViewModel

override fun onCreateView(
    inflater: LayoutInflater, container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {
    // Inflate the layout for this fragment
    binding = FragmentFavouritesBinding.inflate(inflater)

    val application = requireNotNull(this.activity).application
    val datasource = MemesDatabase.getInstance(application).memesDao
    val viewModelFactory = FavouritesViewModelFactory(datasource)
    viewModel = ViewModelProvider(this, viewModelFactory).get(FavouritesViewModel::class.java)


    val adapter = FavouritesAdapter()
    binding.favRecyclerView.adapter = adapter



    viewModel.memesList.observe(viewLifecycleOwner, Observer { memesList ->
        memesList.let {
            adapter.submitList(memesList)
        }
    })

    binding.lifecycleOwner = this



    return binding.root
 }


}

Answer 1

在onCreateViewHolder 中展开视图时，必须将ViewGroup 指定为父视图。

尝试更改

FavouritesViewHolder(MemesListItemBinding.inflate(LayoutInflater.from(parent.context)))

到

FavouritesViewHolder(MemesListItemBinding.inflate(LayoutInflater.from(parent.context), parent, false))

Recyclerview 视图未正确显示列表项

Recyclerview view not displaying list item correctly

android

android-layout

kotlin

android-recyclerview