4

I have created a RecyclerView.Adapter and I want to fill a list.. so my problem now is I don't know how to implement the get position of my list.

below you can see my code:

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    List<Result> _contents;

    public RecyclerViewAdapter(List<Result> contents) {
        this._contents = contents;
    }


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

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int position) {
        View view = null;
        view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.list_item_card_small, parent, false);

        Result tempResult = _contents.get(position);

        TextView temp = (TextView) view.findViewById(R.id.text_city_name);
        temp.setText(tempResult.getInfo().getCity().getName());

        return new RecyclerView.ViewHolder(view) {
        };
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

       }
    }

so the function onCreateViewHolder doesn't get properly the id is always the same id.. how can I fix this or implement to get the right position of mi list?¿ What it´s happening now is the list has the right number of items but is always the same item, the fist one. I guess it´s something simple but I cant figure out how to implement it.

Thanks!!

DeRagan
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gon250
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    So you changed `viewType` to `position` and expected it to now hold a position? – tachyonflux Aug 03 '15 at 23:12
  • Well the position is always the same but it's because I dont know how to implement it. _contents is my list of items so.. How can I get the position there to fill the proper item in my view? Do u know what I mean? @karaokyo – gon250 Aug 03 '15 at 23:14
  • The method signature is: `onCreateViewHolder(ViewGroup parent, int viewType)`. `onCreateViewHolder` will not have a position. You are suppose to populate the view in `onBindViewHolder`. Please check the tutorial and report back if you have any problems: https://developer.android.com/training/material/lists-cards.html. – tachyonflux Aug 03 '15 at 23:20
  • possible duplicate of [RecyclerView android: Getting an item at a particular position](http://stackoverflow.com/questions/28037480/recyclerview-android-getting-an-item-at-a-particular-position) – Jared Burrows Aug 04 '15 at 14:34

3 Answers3

4

I have fixed the issue implementing my own ViewHolder, I was a little bit confused. Below is the code working properly.

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> {

    List<Result> _contents;

    public RecyclerViewAdapter(List<Result> contents) {
        this._contents = contents;
    }


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

    @Override
    public RecyclerViewAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = null;
        view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.list_item_card_small, parent, false);
        return new RecyclerViewAdapter.ViewHolder(view);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        Result tempResult = _contents.get(position);
        holder.mTextView.setText(tempResult.getInfo().getCity().getName());
    }

    public static class ViewHolder extends RecyclerView.ViewHolder {
        public TextView mTextView;
        public ViewHolder(View v) {
            super(v);
            mTextView = (TextView) v.findViewById(R.id.text_city_name);
        }
    }
}
Jason Chueh
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gon250
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3

I'm not sure why you need the position of your list. You can get the position in onBindViewHolder. However, you can put any data you inside ViewHolder and use them later on.

public class RecyclerViewAdapter extends RecyclerView.Adapter<ResultViewHolder> {
    List<Result> _contents;

    public RecyclerViewAdapter(List<Result> contents) {
        this._contents = contents;
    }

    public Result getItem(int position) {
        return _contents != null ? _contents.get(position) : null;
    }

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

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public ResultViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.list_item_card_small, parent, false);
        return new MyViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ResultViewHolder holder, int position;) {
        Result result = getItem(position);
        holder.position = position;
        holder.result = result;
        holder.cityName.setText(result.getInfo().getCity().getName());
    }

    public static class ResultViewHolder extends RecyclerView.ViewHolder implements
            View.OnClickListener {
        int position = -1;
        Result result;
        TextView cityName;

        public ResultViewHolder(View view) {
            super(view);
            cityName = (TextView) view.findViewById(R.id.text_city_name);
            view.setOnClickListener(this);
        }

        public void onClick(View v) {
            // do whatever you want with list posisiton and result...
        }
    }
}
Jason Chueh
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2

onBindViewHolder method recieves position as second argument. you can manipulate your view in this method.

package com.virgooll.avaa.shop.views;


import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import com.virgooll.avaa.R;
import com.virgooll.avaa.detailedIndex.model.StoreItem;

import java.util.List;

public class MasonryAdapter extends RecyclerView.Adapter<MasonryAdapter.StoreItemViewHolder> {
List<StoreItem> items;
int itemsIndex;

public MasonryAdapter(List<StoreItem> items) {
    this.items = items;
}

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

@Override
public MasonryAdapter.StoreItemViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
    itemsIndex = i;
    View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.detailed_index_list_item, viewGroup, false);
    MasonryAdapter.StoreItemViewHolder pvh = new MasonryAdapter.StoreItemViewHolder(v);
    return pvh;
}

@Override
public void onBindViewHolder(MasonryAdapter.StoreItemViewHolder holder, int position) {
    holder.setImage(position);
}

@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
    super.onAttachedToRecyclerView(recyclerView);
}

public class StoreItemViewHolder extends RecyclerView.ViewHolder {
    StoreItemViewHolder(View itemView) {
        super(itemView);
    }

    public void setImage(int position) {
        ImageView image = (ImageView) itemView.findViewById(R.id.detailed_index_fragment_inner_list_view_image);
        image.setImageResource(items.get(position).photoId);
    }
}
}
Hassan Gilak
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