在垂直适配器中添加水平适配器

Question

我需要使用 CocatAdapter 将水平适配器“添加”到垂直适配器。

Answer 1

这是我出来的解决方案：

假设您有一个适配器（垂直方向），它由其他几个适配器组成（

其中一些，水平方向）。如果是这样的话，你可以在 Concat Adapter 和我的类之间使用一个很好的组合。

类是->

class HorizontalListAdapter<T>(
    private val adapter: ListAdapter<T, *>,
) : RecyclerView.Adapter<HorizontalListAdapter.ViewHolder<T>>() {
    override fun onCreateViewHolder(
        parent: ViewGroup,
        viewType: Int,
    ): ViewHolder<T> = ViewHolder(
        parent.inflate(
            R.layout.horizontal_generic_recycler_layout),
            adapter
    )

    class ViewHolder<T>(view: View, private val adapter: ListAdapter<T, *>) :
        RecyclerView.ViewHolder(view) {
        fun bind() {
            itemView.findViewById<RecyclerView>(R.id.recycler_horizontal_generic).adapter = adapter
        }
    }

    override fun getItemViewType(position: Int): Int = R.layout.horizontal_generic_recycler_layout

    fun submitList(list: List<T>) {
        val currentAdapterListItems = adapter.currentList
        if (list != currentAdapterListItems) {
            adapter.submitList(list)
            notifyItemChanged(0)
        }
    }

    override fun onBindViewHolder(holder: ViewHolder<T>, position: Int) {
        holder.bind()
    }
    override fun getItemCount(): Int = 1
}

“通用”xml 是 ->

<?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">

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

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/recycler_horizontal_generic"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            android:paddingHorizontal="4dp"
            app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
            app:layout_constraintTop_toTopOf="parent" />
    </androidx.constraintlayout.widget.ConstraintLayout>
</layout>

最后但同样重要的是，您的 horizontal recycler -> 适配器

class Adapter(private val callback: Callback) :
    ListAdapter<ItemProductPresentation, ViewHolder>(ProductPresentationDiffCallback) {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder =
        ViewHolder(
            ListItemProductPresentationBinding.inflate(
                LayoutInflater.from(parent.context),
                parent,
                false
            ),
            callback
        )

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        holder.bind(getItem(position))
    }

    class ViewHolder(
        private val binding: ListItemProductPresentationBinding,
        private val callback: Callback,
    ) : RecyclerView.ViewHolder(binding.root) {
        fun bind(input: ItemProductPresentation) {
            binding.imgChecked.isVisible = input.selected
        }
    }

    interface Callback { fun onPresentationSelected(presentationItem: ItemProductPresentation) }
}

object ProductPresentationDiffCallback : DiffUtil.ItemCallback<ItemProductPresentation>() {
    override fun areItemsTheSame(
            oldItem: ItemProductPresentation,
            newItem: ItemProductPresentation
    ): Boolean = oldItem.presentation == newItem.presentation

    override fun areContentsTheSame(
            oldItem: ItemProductPresentation,
            newItem: ItemProductPresentation
    ): Boolean = oldItem == newItem
}

所以，在你的视图中 ->

    private val adapter = ConcatAdapter()
    ....
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        horizontalAdapter = HorizontalListAdapter(ProductPresentationAdapter(this))
        adapter.addAdapter(horizontalAdapter)
        binding.recycler.adapter = adapter
    }

查看的 xml ->

<?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">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/lyt_constraint"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@drawable/bkg_white_ffffff_rounded_12">

           <androidx.recyclerview.widget.RecyclerView
                android:id="@+id/recycler"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager" />
        </androidx.constraintlayout.widget.ConstraintLayout>
</layout>

这样，Horizo​​ntalListAdapter 类基本上适应了一个 ListAdapter（你可以让这个类也允许另一种 Adapters ），它应该位于一个更大的垂直滚动适配器内的水平适配器中。在这个例子中，我传递了一个回调，它在视图中工作得很好。

希望这会有所帮助。

谢谢。