在 recyclerview 上检测到 IndexOutOfBoundException 不一致

Question

Hi I am trying to delete an item from recycler view but after successfully deleting when I am scrolling to bottom application is getting crashed and it is showing this error. I tried to call

notifyItemRemoved(position);
notifyItemRangeInserted(position, tasklists.size());

but still its not fixed, I am not sure if I am calling these functions correctly.

2020-05-09 22:09:21.305 10376-10376/com.helpinghandsorg.helpinghands E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.helpinghandsorg.helpinghands, PID: 10376
    java.lang.IndexOutOfBoundsException: Inconsistency detected. Invalid item position 10(offset:10).state:11 androidx.recyclerview.widget.RecyclerView{d7547e3 VFED..... ........ 0,0-1080,1858 #7f0a0159 app:id/recyclerViewTaskLists}, adapter:com.helpinghandsorg.helpinghands.adaptor.MyAdaptor@368f5e0, layout:androidx.recyclerview.widget.LinearLayoutManager@9db2099, context:com.helpinghandsorg.helpinghands.Main2Activity@5c506fd
        at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6183)
        at androidx.recyclerview.widget.GapWorker.prefetchPositionWithDeadline(GapWorker.java:288)
        at androidx.recyclerview.widget.GapWorker.flushTaskWithDeadline(GapWorker.java:345)
        at androidx.recyclerview.widget.GapWorker.flushTasksWithDeadline(GapWorker.java:361)
        at androidx.recyclerview.widget.GapWorker.prefetch(GapWorker.java:368)
        at androidx.recyclerview.widget.GapWorker.run(GapWorker.java:399)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7099)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:965)

MyAdaptor

public class MyAdaptor extends RecyclerView.Adapter<MyAdaptor.myViewHolder> {

    private Context context;
    private ArrayList<TaskModel> taskLists;
    private int counter = 0;
    private Boolean success = false;
    private String taskid;
    private OnTaskClickListner mTaskListner;
    private int newPosition;

    public MyAdaptor(Context c, ArrayList<TaskModel> t, OnTaskClickListner onTaskClickListner) {
        context = c;
        taskLists = t;
        this.mTaskListner = onTaskClickListner;
    }

    @NonNull
    @Override
    public myViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
        View view = layoutInflater.inflate(R.layout.task_preview, parent, false);
        myViewHolder viewHolder = new myViewHolder(view, mTaskListner);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(@NonNull myViewHolder holder, final int position) {
        newPosition = holder.getAdapterPosition();
        holder.title.setText(taskLists.get(position).getTaskTitle());
        holder.dueDate.setText(taskLists.get(position).getDueDate());
        holder.description.setText(taskLists.get(position).getTaskDescription());
        holder.deleteButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                taskid = taskLists.get(position).getTaskID();
                new AlertDialog.Builder(context)
                        .setTitle(R.string.confirm_text)
                        .setMessage(R.string.confirm_text_description)
                        .setPositiveButton(R.string.positive_text, new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                FirebaseDatabase.getInstance()
                                        .getReference("tasks")
                                        .child(taskid)
                                        .removeValue(new DatabaseReference.CompletionListener() {
                                            @Override
                                            public void onComplete(@Nullable DatabaseError databaseError, @NonNull DatabaseReference databaseReference) {
                                                taskLists.remove(position);
                                                notifyItemRemoved(position);
                                                Log.d("tasklist", String.valueOf(taskLists.size()));
                                                notifyItemRangeInserted(position, taskLists.size()-1);
                                                Toast.makeText(context, "Delete Successful", Toast.LENGTH_SHORT).show();
                                            }
                                        });
                            }
                        })
                        .setNegativeButton(R.string.negative_text, new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                dialog.cancel();
                            }
                        }).show();
            }
        });

    }

    @Override
    public int getItemCount() {
        return taskLists.size();
    }

    class myViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        TextView title, dueDate, description;
        ImageButton deleteButton;
        OnTaskClickListner onTaskClickListner;

        public myViewHolder(@NonNull View itemView, OnTaskClickListner onTaskClickListner) {
            super(itemView);
            title = itemView.findViewById(R.id.taskTitle);
            dueDate = itemView.findViewById(R.id.taskDueDate);
            description = itemView.findViewById(R.id.taskDescription);
            deleteButton = itemView.findViewById(R.id.taskDeleteButton);
            this.onTaskClickListner = onTaskClickListner;

            itemView.setOnClickListener(this);

        }

        public ImageButton getDeleteButton() {
            return deleteButton;
        }

        @Override
        public void onClick(View v) {

            onTaskClickListner.onTaskClick(getAdapterPosition());
        }
    }

    public interface OnTaskClickListner {
        void onTaskClick(int position);
    }
}

Answer 1

UPDATE: Change position to holder.getAdapterPosition() when you need position in anonymous class.and make position non final in onBindViewHolder() method;

public void onBindViewHolder(@NonNull final myViewHolder holder, int position)

and:

holder.deleteButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        taskid = taskLists.get(holder.getAdapterPosition()).getTaskID();
        new AlertDialog.Builder(context)
                .setTitle(R.string.confirm_text)
                .setMessage(R.string.confirm_text_description)
                .setPositiveButton(R.string.positive_text, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        FirebaseDatabase.getInstance()
                                .getReference("tasks")
                                .child(taskid)
                                .removeValue(new DatabaseReference.CompletionListener() {
                                    @Override
                                    public void onComplete(@Nullable DatabaseError databaseError, @NonNull DatabaseReference databaseReference) {
                                        taskLists.remove(holder.getAdapterPosition());
                                        notifyItemRemoved(holder.getAdapterPosition());
                                        Log.d("tasklist", String.valueOf(taskLists.size()));

                                        Toast.makeText(context, "Delete Successful", Toast.LENGTH_SHORT).show();
                                    }
                                });
                    }
                })
                .setNegativeButton(R.string.negative_text, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.cancel();
                    }
                }).show();
    }
});

Edit: you must remove notifyItemIRangeInserted() .when you adding items in your list you must call notifyItemIRangeInserted .So just call notifyItemRemoved

Answer 2

When you are deleting an item you are basically reducing the size of your list, so which also means that the size which you are returning from your getItemCount() should also be reduced. Try this: Have a global variable which indicates the size of your list and return that from your getItemCount() when you delete an instance from list, update that variable by decrementing it and then call notifyDataSetChanged()

Answer 3

The issue, you're using a dynamic list and retrieving data directly from a list that is rather dynamic. Instead, you should have a global variable inside your adapter and assign the data to it. Then, whenever the data changes, you can call "notifyDataSetChanged()".