Question

我在实现expandableListView时遇到了一些问题。我实现了我的ExpandableListAdapter

public class ExpandableListAdapter扩展了BaseExpandableListAdapter {

private static final int SUM = 1;
private static final int SUB = 2;

private Context context;
private List<String> listDataHeader;    //Header titles
private HashMap<String, List<Article>> listDataChild;
private HashMap<Integer, Bitmap> productImagesHashMap;

public ExpandableListAdapter (Context context, List<String> listDataHeader, HashMap<String, List<Article>> listDataChild, HashMap<Integer, Bitmap> productImagesHashMap) {
    this.context = context;
    this.listDataHeader = listDataHeader;
    this.listDataChild = listDataChild;
    this.productImagesHashMap = productImagesHashMap;
}

@Override
public int getGroupCount() {
    return this.listDataHeader.size();
}

@Override
public int getChildrenCount(int groupPosition) {
    return this.listDataChild.get(this.listDataHeader.get(groupPosition)).size();
}

@Override
public Object getGroup(int groupPosition) {
    return this.listDataHeader.get(groupPosition);
}

@Override
public Object getChild(int groupPosition, int childPosition) {
    return this.listDataChild.get(this.listDataHeader.get(groupPosition)).get(childPosition);
}

@Override
public long getGroupId(int groupPosition) {
    return groupPosition;
}

@Override
public long getChildId(int groupPosition, int childPosition) {
    return childPosition;
}

@Override
public boolean hasStableIds() {
    return false;
}

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {

    String headerTitle = (String) getGroup(groupPosition);
    if (convertView == null) {
        LayoutInflater layoutInflater = (LayoutInflater) this.context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = layoutInflater.inflate(R.layout.user_expand_listview_header, null);
    }

    TextView listHeaderTextView = (TextView) convertView.findViewById(R.id.list_header);
    listHeaderTextView.setTypeface(null, Typeface.BOLD);
    listHeaderTextView.setText(headerTitle);

    return convertView;
}

@Override
public View getChildView(final int groupPosition, final int childPosition,
                         boolean isLastChild, View convertView, ViewGroup parent) {

    final Article childValues = (Article) getChild(groupPosition, childPosition);

    if (convertView == null) {
        LayoutInflater layoutInflater = (LayoutInflater) this.context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = layoutInflater.inflate(R.layout.product_row, null);
    }

    Integer articleId = childValues.getId();

    final TextView articleIdTextView = (TextView) convertView.findViewById(R.id.product_id);
    ImageView productImageTextView = (ImageView) convertView.findViewById(R.id.product_image);
    TextView productNameTextView = (TextView) convertView.findViewById(R.id.product_name);
    TextView productDescriptionTextView = (TextView) convertView.findViewById(R.id.product_description);
    final TextView productPriceTextView = (TextView) convertView.findViewById(R.id.product_price);

    articleIdTextView.setText(articleId.toString());
    productImageTextView.setImageBitmap(productImagesHashMap.get(articleId));
    productNameTextView.setText(childValues.getNome());
    productDescriptionTextView.setText(childValues.getDescrizione());
    productPriceTextView.setText(childValues.getPrezzo());

    ImageButton addButton = (ImageButton) convertView.findViewById(R.id.add_btn);
    final TextView articleQty =(TextView) convertView.findViewById(R.id.product_qnty);
    ImageButton removeButton = (ImageButton) convertView.findViewById(R.id.remove_btn);

    addButton.setOnClickListener(new Button.OnClickListener() {

        @Override
        public void onClick(View view) {
            if (context instanceof UserActivity) {
                ((UserActivity) context).updateTotal(
                        Integer.parseInt(articleIdTextView.getText().toString()),
                        productPriceTextView.getText().toString(),
                        SUM);
                articleQty.setText(updateProductQty(articleQty, SUM));
            }
        }
    });

    removeButton.setOnClickListener(new Button.OnClickListener() {

        @Override
        public void onClick(View view) {
            if (context instanceof UserActivity) {
                ((UserActivity) context).updateTotal(
                        Integer.parseInt(articleIdTextView.getText().toString()),
                        productPriceTextView.getText().toString(),
                        SUB);
                articleQty.setText(updateProductQty(articleQty, SUB));
            }
        }
    });

    return convertView;
}

@Override
public boolean isChildSelectable(int i, int i1) {
    return true;
}

private String updateProductQty(TextView productQty, int operation) {
    Integer qty = Integer.parseInt(productQty.getText().toString());
    switch (operation) {
        case 1: //SUM
            qty += 1;
            break;
        case 2: //SUB
            if (qty > 0)
                qty -= 1;
            break;
    }
    return qty.toString();
}

}

有些产品从数据库中读取并按类型插入ExpandableListView（实际钢笔，笔记本和纸张）。然后有两个按钮，允许选择用户想要购买的数量，数量由TextView跟踪。现在，当我使用普通的ListView实现这一切时，所有工作都有效，但是使用ExpandableListView时，孩子的数量TextView之间存在干扰。

例如，ExpandableListView的实际组成是：

笔

- 黑笔

- 蓝笔

- 红笔

笔记本

- 黑色笔记本</ p>

- Blue Notebook

- 红色笔记本</ p>

纸张

- A4纸

如果用户添加黑色笔记本，还会添加蓝色笔

如果用户添加蓝色笔记本，还会添加黑色笔

如果用户添加红色笔记本，还会添加蓝色笔

为什么会有这些干扰？

Answer 1

您没有正确跟踪数量更新。

由于ExpandableListView - 与ListView一样 - 回收其观点，您会遇到以下行为：

用户按下黑色笔记本的添加按钮。
用户滚动/展开/折叠列表。
通过回收黑色笔记本中的视图来创建蓝色笔的视图。
蓝色笔的视图显示黑色笔记本的数量。

这是你需要做的：

将数量属性添加到Article类
创建子视图时，请使用articleQty对象中包含的数量填充TextView Article。
当用户按下添加/删除按钮时，更新Article对象中的数量并致电notifyDataSetChanged()。

规则是：从模型中填充视图，从侦听器更新模型。不要使用监听器来更新视图，调用notifyDataSetcChanged()将会解决这个问题。

expandableListView子级之间的干扰

1 个答案: