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Android

Posted by Kevin Faust
Kevin Faust
15,353 Points

How to delete a row in RecyclerView (having 2 problems)

Hey everyone,

What I have right now is a delete method inside my Adapter class:

delete.java 
    public void delete(int position) {
        mNumbers.remove(position);
        notifyItemRemoved(position);
    }

The problem i'm having is where to set my onclick listener. In treehouse we generally used our onclick listener inside of our ViewHolder class. However someone on stackoverflow said never to do that and to do it in my bind method instead.

So I tried it both ways and came across a problem both ways

OnBind

I set my onclick listener inside it and then write the following:

delete(getAdapterPosition())

I'm trying to use the getAdapterPosition method to delete the current recyclerview row however android is saying this method doesn't exist

I also tried to just pass in the "position" given by the OnBind method however my app was acting all wonky and things werent getting deleted properly

In ViewHolder

I set my onclick listener here and write the same as above. At least the getAdapterPosition method is recognized by android here however now I get this error: non static method cannot be referenced from a static context

Thanks to anyone that can help,

Kevin

Kevin Faust
Kevin Faust
15,353 Points

maybe im not even doing it right and there is a simpler way?

Seth Kroger
Seth Kroger
56,416 Points

Code? It's not entirely clear what you're trying to do from those snippets. Is there a delete button in each list item you click, or are you tapping the item to delete? Did you declare the view holder as a static class? (if it is, you can't call instance methods of the containing adapter because there's no back reference to it.)

Kevin Faust
Kevin Faust
15,353 Points

I fixed the problem by removing the static keyword:. Im wondering if this is the most efficient way to do this. Others have said this is just a quick fix and that i should use the static keyword to increase performance. Thoughts?

Below is simply just a textview, edittext, checkbox, and a delete button

Adapter.java 
public class myAdapter extends RecyclerView.Adapter<myAdapter.ViewHolder> {

    private List<numbers> mNumbers = Collections.emptyList();

    public myAdapter (List<numbers> numbers) {
        mNumbers = numbers;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View v  = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_slot, parent, false);
        ViewHolder vh = new ViewHolder(v);
        return vh;
    }


    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        holder.bindNumbers(mNumbers.get(position));
    }

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

    public void delete(int position) { //removes the row
        mNumbers.remove(position);
        notifyItemRemoved(position);
    }



    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

        TextView numberText;
        EditText checklistText;
        Button deleteButton;
        CheckBox checkDisBox;

        public ViewHolder(View itemView) {
            super(itemView);
            numberText = (TextView) itemView.findViewById(R.id.number);
            checklistText = (EditText) itemView.findViewById(R.id.editText);
            deleteButton = (Button) itemView.findViewById(R.id.deleteButton);
            checkDisBox = (CheckBox) itemView.findViewById(R.id.checkBox);

            deleteButton.setOnClickListener(this); //button onclick listener



        }

        public void bindNumbers(numbers numbers) {
            numberText.setText(numbers.getInt() + "");
        }

        @Override
        public void onClick(View v) {
            delete(getAdapterPosition()); //calls the method above to delete
        }
    }
}