Question

我决定使用新的 RecyclerView.ListAdapter ，并尝试将其用于生产。

我的计划是在加载列表项时显示一个占位符（骨架）项，然后在客户端接收到数据后切换到普通项列表。我在 adapter 中处理此问题的方式是，将一个'null'传递给 submitList（）（这样我就知道数据尚未加载）。

第一部分效果很好， ListAdapter 启动并显示框架项，但是一旦加载了“真实”列表，应用程序就会崩溃。崩溃的原因是 adapter 直接进入 onBindViewHolder（）而不先调用 onCreateViewHolder（），因此该尝试绑定数据到骨架项目中不存在的普通项目的字段。

到目前为止，我还无法找出为什么它跳过了第一项的 onCreateViewHolder（）部分并直接进入绑定的原因。我检查了 diffUtils 是否存在问题，但是两个项目（框架项目和“真实”项目）明显不同。（这里的简短说明：由于某些原因，两个 diffUtils 函数中的断点根本不会触发..我不确定这是否也是问题的一部分，或者仅仅是 Android Studio 问题。）

重要的主要类别：

ListAdapter

class VIPSimilarAdsAdapter(context: Context, presenterInterface: BaseVIPContract.MVPAdapterPresenter) : ListAdapter<Ad, AdViewHolderFactory.AdBaseViewHolder>(SimilarAdsDiffCallback()) {

    private val presenterInterface: WeakReference<BaseVIPContract.MVPAdapterPresenter> = WeakReference(presenterInterface)
    private var showLoadingInidicator = true

    override fun submitList(list: List<Ad>?) {
        showLoadingInidicator = list == null
        super.submitList(list)
    }

    override fun getItemCount(): Int {
        return when (showLoadingInidicator) {
            true -> 1
            else -> super.getItemCount()
        }
    }

    override fun onBindViewHolder(@NonNull holder: AdViewHolderFactory.AdBaseViewHolder, position: Int) {
        if (!showLoadingInidicator) {
            getItem(position)?.let { safeAd ->
                CommonViewBinder.bindCommonFields(holder as AdViewHolderFactory.AdViewHolder, safeAd)
                AdViewBinder.bindAdFields(holder, safeAd)
                holder.itemView.setOnClickListener {
                    presenterInterface.get()?.onUserEventSimilarAdClicked(safeAd, position)
                }
            }
        }
    }

    @NonNull
    override fun onCreateViewHolder(@NonNull parent: ViewGroup, viewType: Int): AdViewHolderFactory.AdBaseViewHolder {
        return (when (showLoadingInidicator) {
            true -> AdViewHolderFactory.SkeletonViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.grid_item_skeleton, parent, false), ITEM_VIEW_TYPE_SKELETON)
            else -> AdViewHolderFactory.AdViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.grid_item_ad_basic, parent, false))
        })
    }
}

DiffUtil回调

class SimilarAdsDiffCallback : DiffUtil.ItemCallback<Ad>() {
    override fun areItemsTheSame(oldItem: Ad, newItem: Ad): Boolean {
        return oldItem == newItem
    }

    override fun areContentsTheSame(oldItem: Ad, newItem: Ad): Boolean {
        return oldItem.id == newItem.id
    }
}

适配器的简称是

adAdapterSimilarAds.submitList(null)

在活动开始时使用

adAdapterSimilarAds.submitList(list)

一旦我们加载了数据。

希望任何人以前都遇到过这个问题，可以帮助我...

编辑：这是崩溃的堆栈跟踪

java.lang.IndexOutOfBoundsException: Inconsistency detected. Invalid view holder adapter positionViewHolder{4e5bcfd position=6 id=-1, oldPos=0, pLpos:0 scrap [attachedScrap] tmpDetached no parent} androidx.recyclerview.widget.RecyclerView{3d89e2f VFED..... ......ID 0,1953-1080,2289 #7f090302 app:id/similar_ads_after_pos_1}, adapter:ebk.vip.similar_ads.VIPSimilarAdsAdapter@ac7dc3c, layout:androidx.recyclerview.widget.GridLayoutManager@e9b3dc5, context:ebk.vip.vip_core.VIPActivity@ecfbcc3
        at androidx.recyclerview.widget.RecyclerView$Recycler.validateViewHolderForOffsetPosition(RecyclerView.java:5715)
        at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5898)
        at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5858)
        at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5854)
        at androidx.recyclerview.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2230)
        at androidx.recyclerview.widget.GridLayoutManager.layoutChunk(GridLayoutManager.java:557)
        at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1517)
        at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:612)
        at androidx.recyclerview.widget.GridLayoutManager.onLayoutChildren(GridLayoutManager.java:171)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep1(RecyclerView.java:3875)
        at androidx.recyclerview.widget.RecyclerView.onMeasure(RecyclerView.java:3330)
        at android.view.View.measure(View.java:19857)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:758)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:640)
        at android.view.View.measure(View.java:19857)
        at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:715)
        at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:461)
        at android.view.View.measure(View.java:19857)
        at androidx.core.widget.NestedScrollView.measureChildWithMargins(NestedScrollView.java:1502)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at androidx.core.widget.NestedScrollView.onMeasure(NestedScrollView.java:556)
        at android.view.View.measure(View.java:19857)
        at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:715)
        at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:461)
        at android.view.View.measure(View.java:19857)
        at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:715)
        at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:461)
        at android.view.View.measure(View.java:19857)
        at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:715)
        at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:461)
        at android.view.View.measure(View.java:19857)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at androidx.appcompat.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143)
        at android.view.View.measure(View.java:19857)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.view.View.measure(View.java:19857)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
        at android.view.View.measure(View.java:19857)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:758)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:640)

更改数据时，RecyclerView.ListAdapter崩溃

0 个答案: