Inconsistency detected Invalid view holder adapter position"

2,466 阅读1分钟

RecyclerView在添加数据的时候发生了异常.

java.lang.IndexOutOfBoundsException: Inconsistency detected. Invalid view holder adapter positionViewHolder{f82aa71 position=11 id=-1, oldPos=6, pLpos:6 scrap [attachedScrap] tmpDetached not recyclable(1) no parent}
     at android.support.v7.widget.RecyclerView$Recycler.validateViewHolderForOffsetPosition(RecyclerView.java:5297)
     at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5479)
     at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5440)
     at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5436)
     at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2224)
     at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1551)
     at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1511)
     at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:595)
     at android.support.v7.widget.RecyclerView.dispatchLayoutStep1(RecyclerView.java:3534)
     at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3310)
  ...

RecyclerView#validateViewHolderForOffsetPosition(ViewHolder holder)

if (holder.mPosition < 0 || holder.mPosition >= mAdapter.getItemCount()) {
                throw new IndexOutOfBoundsException("Inconsistency detected. Invalid view holder "
                        + "adapter position" + holder);
            }

holder.mPosition >= mAdapter.getItemCount()为真,抛出了异常 发现mAdapter.getItemCount() 的值是正常的,但是holder.mPosition值有问题,在某种情况下和getItemCount的值一样大,此时条件为真。

接下来看了下RecyclerView中有5个方法改变了mPosition的值,分别是

  • Adapter#bindViewHolder()
  • ViewHolder#resetInternal()
  • ViewHolder#offsetPosition()
  • ViewHolder#flagRemovedAndOffsetPosition()
  • Recycler#tryGetViewHolderForPositionByDeadline()

分别打了断点,发现会引起崩溃的代码,会改变mPosition的有其中三个地方resetInternal()offsetPosition()bindViewHolder()resetInternal() 首先排除 ,因为mPosition = NO_POSITION;

然后仔细查看offsetPosition()bindViewholder()中的值发现,offsetPosition()的值mPosition += offset;会超出mPosition的值的范围。 所以现在就要去找这个方法被调用的时机和offset这个值的含义

  1. 查看offsetPosition()的调用,发现调用分别来自RecyclerView与RecyclerView.Recycler两个的对应的insert,moveremove方法,以及ViewHolderflagRemovedAndOffsetPosition(int, int, boolean)的方法 主要看就下面这个
void offsetPositionRecordsForInsert(int positionStart, int itemCount) {
  //...
   //这里将itemCount 传递给了offsetPosition
               holder.offsetPosition(itemCount, false);
 //...
       mRecycler.offsetPositionRecordsForInsert(positionStart, itemCount);
       requestLayout();
   }

看起来在某个刷新数据的地方理解错了itemCount,找到我自己Adapter代码里面的 notifyItemRangeInserted(positionStart,itemCount);暂时修改为notifyDataSetChanged()不会报错了