Question

在我的recyclerview中有一个imageview和textview。我正在更改ImageView on onClickListener的图像。现在的问题是，如果我点击位置3的图像并向下滚动...位置8的图像也会改变，如果我向上滚动......位置2的图像也会改变。

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

Context context;
static    List<PortraitParentListAdapterBean> list;
static List<String> selectedPosition ;

public PortraitListviewAdapter(Context context, List<PortraitParentListAdapterBean> list) {
    this.context = context;
    this.list = list;
    selectedPosition = new ArrayList<>();
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View itemView = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.listview_parent_portrait, parent, false);

    return new ViewHolder(itemView);
}
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {

    PortraitParentListAdapterBean portBean = list.get(position);
    Log.i("pos",position+"");
    holder.parentHeading.setText(portBean.getHeading());
    if (selectedPosition.contains(list.get(position).getHeading())){
        holder.parentImage.setImageResource(R.drawable.sad);
    }


}

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

static class ViewHolder extends RecyclerView.ViewHolder {
    protected TextView parentHeading;
    protected ImageView parentImage;

    public ViewHolder(View itemView) {
        super(itemView);

        parentHeading = (TextView)itemView.findViewById(R.id.parent_heading);
        parentImage = (ImageView)itemView.findViewById(R.id.imageView);

        itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                selectedPosition.add(list.get(getAdapterPosition()).getHeading());
                parentImage.setImageResource(R.drawable.sad);
            }
        });
    }
}

}

上面的代码是我对recyclerview适配器的实现。请帮助理解这个概念。

Answer 1

<强>解

变化

if (selectedPosition.contains(list.get(position).getHeading())){
        holder.parentImage.setImageResource(R.drawable.sad);
}

与

if (selectedPosition.contains(list.get(position).getHeading())){
        holder.parentImage.setImageResource(R.drawable.sad);
} else {
        holder.parentImage.setImageResource(R.drawable.your_default_drawable);
}

<强>说明

当您滚动RecyclerView时，系统不会重新创建您的ViewHolder，而是重复使用之前滚动的不再可见的视频，因此您需要重置标准值以避免显示错误的值。

在滚动时取消选择recyclelerview中的选定图像

1 个答案: