问题描述：

不添加grid item及之后的item，可以显示。添加了就不能显示。

相关截图：

相关代码：

package org.devio.`as`.hi.hiitem.hiitem2

import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView

abstract class HiDataItem<DATA, VH : RecyclerView.ViewHolder>(data: DATA?) {

    val TAG: String = "HiDataItem"
    private var mAdapter: HiAdapter? = null
    var mData: DATA? = null

    init {
        this.mData = data
    }

    abstract fun onBindData(holder: VH, position: Int)

    /**
     * 返回item布局文件id
     */
    open fun getLayoutRes(): Int {
        return -1;
    }

    /**
     * 返回item view
     */
    open fun getItemView(parent: ViewGroup): View? {
        return null
    }

    fun setAdapter(adapter: HiAdapter) {
        this.mAdapter = adapter
    }

    /**
     * 刷新列表
     */
    fun refreshItem() {
        if (mAdapter != null) {
            mAdapter!!.refreshItem(this)
        }
    }

    /**
     * 移除item
     */
    fun removeItem() {
        if (mAdapter != null) {
            mAdapter!!.removeItem(this)
        }
    }

    /**
     * 此item在列表中占有几列???
     */
    open fun getSpanSize(): Int {
        return 0
    }

    //提供空实现，子类可以实现，也可以不实现
    open fun onViewAttachedToWindow(holder: VH){

    }

    open fun onViewDetachedFromWindow(holder: VH) {

    }


}
      
​package org.devio.`as`.hi.hiitem.hiitem2

import android.content.Context
import android.util.SparseArray
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.GridLayoutManager
import androidx.recyclerview.widget.RecyclerView
import androidx.recyclerview.widget.StaggeredGridLayoutManager
import java.lang.ref.WeakReference
import java.lang.reflect.ParameterizedType

class HiAdapter(context: Context) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {

    private val mRecylerViewRef: WeakReference<RecyclerView>? = null
    private var mContext: Context
    private var mLayoutInflater: LayoutInflater? = null
    private var mDataSet = java.util.ArrayList<HiDataItem<*, out RecyclerView.ViewHolder>>()
    private var mTypeArrays = SparseArray<HiDataItem<*, out RecyclerView.ViewHolder>>()

    init {
        mContext = context
        mLayoutInflater = LayoutInflater.from(mContext)
    }

    /**
     * 在指定索引处添加hidataitem
     */
    fun addItemAt(index: Int, dataItem: HiDataItem<*, out RecyclerView.ViewHolder>, notify: Boolean) {
        if (index > 0) {
            mDataSet.add(index, dataItem)
        } else {
            mDataSet.add(dataItem)
        }

        val notifyPos = if (index > 0) index else mDataSet.size - 1
        if (notify) {
            notifyItemInserted(notifyPos)
        }

    }

    /**
     * 往现有集合末加mDataSet
     */
    fun addItems(items: ArrayList<HiDataItem<*, out RecyclerView.ViewHolder>>, notify: Boolean) {
        val start = items.size

        for (item in items) {
            mDataSet.add(item)
        }

        if (notify) {
            notifyItemRangeChanged(start, items.size)
        }
    }

    /**
     * 删除指定索引处的item
     */
    fun removeItemAt(index: Int): HiDataItem<*, out RecyclerView.ViewHolder>? {
        if (index > 0 && index < mDataSet.size) {
            val remove = mDataSet.removeAt(index)
            notifyItemRemoved(index)
            return remove
        } else {
            return null
        }
    }

    /**
     * 删除指定item
     */
    fun removeItem(item: HiDataItem<*, out RecyclerView.ViewHolder>) {
        val index = mDataSet.indexOf(item)
        removeItemAt(index)
    }

    /**
     * 刷新指定的item
     */
    fun refreshItem(item: HiDataItem<*, out RecyclerView.ViewHolder>) {
        val indexOf = mDataSet.indexOf(item)
        notifyItemChanged(indexOf)
    }

    //将每一种item class hashcode 作为此item的type
    override fun getItemViewType(position: Int): Int {
        val item = mDataSet.get(position)
        val type = item.javaClass.hashCode()
        if (mTypeArrays.indexOfKey(type) < 0) {
            mTypeArrays.put(type, item)
        }
        return type
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        val dataItem = mTypeArrays.get(viewType);
        var view = dataItem.getItemView(parent)
        if (view == null) {
            val layoutRes = dataItem.getLayoutRes()
            if (layoutRes < 0) {
                RuntimeException("dataItem : " + dataItem.javaClass.simpleName + " must override getItemView or getLayoutRes")
            }
            view = mLayoutInflater!!.inflate(layoutRes, parent, false)
        }

        return createViewHolderInternal(dataItem.javaClass, view!!)
    }

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {

        val dataItem = getItem(position)
        if (dataItem != null) {
            dataItem.onBindData(holder, position)//会不会强转???
        }
    }

    fun getItem(position: Int): HiDataItem<*, RecyclerView.ViewHolder>? {
        if (position < 0 || position >= mDataSet.size) {
            return null
        }

        return mDataSet[position] as HiDataItem<*, RecyclerView.ViewHolder>
    }

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

    private fun createViewHolderInternal(javaClass: Class<HiDataItem<*, out RecyclerView.ViewHolder>>, view: View): RecyclerView.ViewHolder {
        //判断是不是参数泛型
        val superClass = javaClass.genericSuperclass
        if (superClass is ParameterizedType) {
            //得到泛型参数数组
            val arguments = superClass.actualTypeArguments
            for (argument in arguments) {
                if (argument is Class<*> && RecyclerView.ViewHolder::class.java.isAssignableFrom(argument)) {
                    try {
                        argument.getConstructor(View::class.java).newInstance(view) as RecyclerView.ViewHolder
                    } catch (e: Throwable) {
                        e.printStackTrace()
                    }
                }
            }
        }

        return object : RecyclerView.ViewHolder(view) {}
    }

    //???
    /**
     * 为列表上的部分Item,适配网格布局
     */
    override fun onAttachedToRecyclerView(recyclerView: RecyclerView) {
        super.onAttachedToRecyclerView(recyclerView)

        val layoutManager = recyclerView.layoutManager
        if (layoutManager is GridLayoutManager) {
            val spanCount = layoutManager.spanCount
            layoutManager.spanSizeLookup = object : GridLayoutManager.SpanSizeLookup() {
                //行数 每行Item数=spanCount/spanSize
                override fun getSpanSize(position: Int): Int {
                    if (position < mDataSet.size) {
                        val dataItem = getItem(position)
                        if (dataItem != null) {
                            val spanSize = dataItem.getSpanSize()//???
                            return if (spanSize <= 0) spanCount else spanSize //只有1行或多行的处理???
                        }
                    }

                    return spanCount
                }
            }
        }
    }

    override fun onDetachedFromRecyclerView(recyclerView: RecyclerView) {
        super.onDetachedFromRecyclerView(recyclerView)
        if (mRecylerViewRef != null) {
            mRecylerViewRef.clear()
        }
    }

    /**
     * 当view滑入屏幕时 ???
     */
    override fun onViewAttachedToWindow(holder: RecyclerView.ViewHolder) {
        val recyclerView = getAttachRecyclerView()
        if (recyclerView != null) {
            val position = recyclerView!!.getChildAdapterPosition(holder.itemView)
            val dataItem = getItem(position)
            if (dataItem == null) return
            val lp = holder.itemView.layoutParams
            if (lp != null && lp is StaggeredGridLayoutManager.LayoutParams) {
                val manager = recyclerView.layoutManager as StaggeredGridLayoutManager
                val spanSize = dataItem.getSpanSize()//???
                if (spanSize == manager!!.spanCount) {
                    lp.isFullSpan = true
                }
            }

            //添加item自定义处理
            dataItem.onViewAttachedToWindow(holder)
        }
    }

    private fun getAttachRecyclerView(): RecyclerView? {
        return if (mRecylerViewRef != null) mRecylerViewRef.get() else null
    }


    /**
     * 当view滑出屏幕
     */
    override fun onViewDetachedFromWindow(holder: RecyclerView.ViewHolder) {
        val dataItem = getItem(holder.adapterPosition)
        if (dataItem == null) return
        dataItem.onViewDetachedFromWindow(holder)
    }


}

子类的item用的是你写的

尝试过的解决方式：

通过打断点和日志发现，adpater onbindata没有判断当item是grid item时，将holder强转为自定义holder,这个应该是要加上的吧？我不确定。但项目中没有加。