java - ListView ViewHolder 项目 subview 可见性改变

Question

我有一个带有自定义ArrayAdapter的ListView。问题是我无法在某些选择的元素中隐藏 (setVisibility(View.GONE)) TextView 。这是我的代码的最小化可读摘要部分:

public class ListViewAdapter extends ArrayAdapter<ItemModel> {

    private int listItemLayout;

    static class ViewHolder {
        private TextView description;
    }

    public ListViewAdapter(Context context, int layoutId, List<ItemModel> itemList) {
        super(context, layoutId, itemList);
        this.listItemLayout = layoutId;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ItemModel item = getItem(position);
        ViewHolder viewHolder;
        if (convertView == null) {
            viewHolder = new ViewHolder();
            convertView = LayoutInflater.from(getContext()).inflate(listItemLayout, parent, false);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }
        viewHolder.description = convertView.findViewById(R.id.text_desription);
        viewHolder.description.setText(item.getDescription());
        if (TextUtils.isEmpty(item.getDescription())) {
            viewHolder.description.setVisibility(View.GONE);
        }
        return convertView;
    }
}

我在这里做错了什么？如果其内容 String 为空，如何隐藏 ListView 中项目内的 View ？

Answer 1

添加 if 条件的 else 部分，将可见性从 GONE 更改为 VISIBLE，如下面的代码所示。

public class ListViewAdapter extends ArrayAdapter {

    private int listItemLayout;

    static class ViewHolder {
        private TextView description;
    }

    public ListViewAdapter(Context context, int layoutId, List itemList) {
        super(context, layoutId, itemList);
        this.listItemLayout = layoutId;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ItemModel item = getItem(position);
        ViewHolder viewHolder;
        if (convertView == null) {
            viewHolder = new ViewHolder();
            convertView = LayoutInflater.from(getContext()).inflate(listItemLayout, parent, false);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }
        viewHolder.description = convertView.findViewById(R.id.text_desription);
        viewHolder.description.setText(item.getDescription());
        if (TextUtils.isEmpty(item.getDescription())) {
            viewHolder.description.setVisibility(View.GONE);
        }else{
            viewHolder.description.setVisibility(View.VISIBLE);
        }
        return convertView;
    }
}

或者
尝试if (item.getDescription()==null || item.getDescription().trim().length() == 0) 而不是 if (TextUtils.isEmpty(item.getDescription()))