IndexOutOfBoundsException on getRef().removeValue in FirebaseRecyclerAdapter

Question

我遇到了这个异常：

java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0

使用此代码时：

mAdapter = new FirebaseRecyclerAdapter<Campaign, CampaignHolder>(Campaign.class, R.layout.recyclerview_template, CampaignHolder.class, ref) {
        @Override
        public void populateViewHolder(final CampaignHolder viewHolder, final Campaign campaign, final int position) {
            final String key = campaign.x;
            FirebaseDatabase.getInstance().getReference().child("x").addValueEventListener(new ValueEventListener() {
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {
                    if (!dataSnapshot.hasChild(key)) {
                        getRef(position).removeValue(new DatabaseReference.CompletionListener() { //Crash here
                            @Override
                            public void onComplete(DatabaseError databaseError, DatabaseReference databaseReference) {
                                if (databaseError != null)
                                    FirebaseCrash.report(databaseError.toException());
                                else{
                                    if (mAdapter.getItemCount() == 0){
                                        v.findViewById(R.id.empty).setVisibility(View.VISIBLE);
                                    }
                                }

                            }
                        });

                        return;
                    }
                    //...
            }

在这一行：

  getRef(position).removeValue(new DatabaseReference.CompletionListener() {

（我用 x 替换了一些字符串，因为我想保密）

导致此问题的原因是什么？我该如何解决？

Answer 1

我把这个解决了：

DatabaseReference ref = getRef(position);

内部class之外，然后使用ref代替getRef()。至少我认为这为我解决了。

Answer 2

此问题的正确解决方案在这里：

You should not use position outside of populateViewHolder as it value may differ. Instead, make your viewHolder final and use viewHolder.getAdapterPosition() to replace it.

IndexOutOfBoundsException on getRef().removeValue in FirebaseRecyclerAdapter

IndexOutOfBoundsException on getRef().removeValue in FirebaseRecyclerAdapter

android

indexoutofboundsexception

firebase

firebase-realtime-database

firebaseui