RecyclerView.Adapter 获取我列表中的项目位置

Question

我创建了一个 RecyclerView.Adapter 并且我想填充一个列表..所以我现在的问题是我不知道如何实现列表的获取位置。

下面你可以看到我的代码：

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) {

       }
    }

所以函数 onCreateViewHolder 没有得到正确的 ID 总是相同的 ID.. 我该如何解决这个问题或实现以获得 mi 列表的正确位置？列表中的项目数量正确，但始终是相同的项目，即第一个。我想这很简单，但我不知道如何实现它。

谢谢！！

Answer 1

我不确定您为什么需要列表的位置。您可以在onBindViewHolder中获取位置。但是，您可以将任何数据放入 ViewHolder 并在以后使用它们。

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...
        }
    }
}

Answer 2

我已经解决了实现我自己的 ViewHolder 的问题，我有点困惑。下面是正常工作的代码。

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);
        }
    }
}

Answer 3

onBindViewHolder 方法接收位置作为第二个参数。你可以在这个方法中操作你的视图。

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);
    }
}
}

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