Question

我想用交替的颜色更改我的RecyclerView项目背景。

这是Adapter中的方法。

public class NewsAdapter extends RecyclerView.Adapter<NewsAdapter.ViewHolder> {
private List<NewsModel> mNewsList;

class ViewHolder extends RecyclerView.ViewHolder {
    TextView newsNameText;
    TextView newsDataText;
    View listView;
    public ViewHolder(View newsView) {
        super(newsView);
        newsNameText = (TextView) newsView.findViewById(R.id.news_Name);
        newsDataText = (TextView) newsView.findViewById(R.id.news_Data);
        listView = newsView;
    }
}
public NewsAdapter(List<NewsModel> newsList) {
    mNewsList = newsList;
}
@Override
public  ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.news_item, parent, false);
    final ViewHolder holder = new ViewHolder(view);
    return holder;
}
public void setData(List<NewsModel> viewData) {
    mNewsList.clear();
    mNewsList.addAll(viewData);
    notifyDataSetChanged();
}

@Override
public void onBindViewHolder(ViewHolder holder, int position) {
    NewsModel news = mNewsList.get(position);
    holder.setIsRecyclable(true);
    if(position % 2 == 0){
        holder.listView.setBackgroundColor(0x80E0EEEE);
    }
    holder.newsNameText.setText(news.getName());
    holder.newsDataText.setText(news.getData());
}
@Override
public int getItemCount() {
    return mNewsList.size();
}

}

问题是当我触摸屏幕并向下滑动以查看更多项目时，项目背景颜色变得乱序。它没有交替。

使用这种方法我错了吗？

谢谢！

Answer 1

这是因为RecyclerView会回收旧视图以创建新视图。当您向下滚动时，旧视图用于创建新视图，因为在调用onBindViewHolder时已经设置了这些旧视图的背景颜色，您必须在onBindViewHolder中指定else条件改变颜色并保持交替的颜色顺序。将您的onBindViewHolder代码更改为：

@Override
public void onBindViewHolder(ViewHolder holder, int position) {
    NewsModel news = mNewsList.get(position);
    holder.setIsRecyclable(true);
    if(position % 2 == 0){
        holder.listView.setBackgroundColor(0x80E0EEEE);
    }else{
        holder.listview.setBackgroundColor(#FFFFFF);
    }
    holder.newsNameText.setText(news.getName());
    holder.newsDataText.setText(news.getData());
}

Answer 2

试试这个

NewsModel news = mNewsList.get(getAdapterPosition());
holder.setIsRecyclable(true);
if(getAdapterPosition() % 2 == 0){
    holder.listView.setBackgroundColor(0x80E0EEEE);
}else{
     holder.listView.setBackgroundColor(000000); // use default color
}

RecyclerView项目背景交替颜色无序

2 个答案: