尝试将 RowItem 添加到 ListView 时出现 Android IndexOutOfBoundsException

Question

我正在尝试从 JSON 对象中提取一些数据以插入到添加到 ListView 的 CustomRowItem 中，JSON 被提取得很好，但是当我尝试将数据添加到行项目时，我得到了：@987654321 @错误。

完整代码如下：

    protected void parseJsonToCurrencyRowItem(Currency cryptoCurrency) {
    try {
        for (int i = 0; i < returnedJsonArrayResult.length(); i++) {
            JSONObject jOb = returnedJsonArrayResult.getJSONObject(i);
            cryptoCurrency.jsonCurrencyName.add(jOb.getString("name"));
            cryptoCurrency.jsonCurrencyName.add(jOb.getString("percent_change_24h"));
            cryptoCurrency.jsonCurrencyName.add(jOb.getString("price_gbp"));
            cryptoCurrency.jsonCurrencyName.add(jOb.getString("24h_volume_gbp"));
            drawListRows(cryptoCurrency, i);
        }


    } catch (Exception e) {
        Log.d("ERROR", e.toString());
    }

}

protected void drawListRows(Currency currency, int i) {
    CurrencyRowItem item = new CurrencyRowItem(currency.jsonCurrencyName.get(i), currency.jsonCurrencyPrice.get(i), currency.jsonPercentchange24hr.get(i), currency.jsonVolume24hr.get(i));
    rowItemList.add(item);
    adapter.notifyDataSetChanged();
}

代码在CurrencyRowItem item = new CurrencyRowItem(currency.jsonCurrencyName.get(i), currency.jsonCurrencyPrice.get(i), currency.jsonPercentchange24hr.get(i), currency.jsonVolume24hr.get(i)); 上失败 Line 和它正在努力解决这个问题，提前感谢您的帮助。

适配器代码

public class BrowseCustomAdapter extends BaseAdapter {
    List<CurrencyRowItem> listingRowItems;
    Context context;

    BrowseCustomAdapter(Context context, List<CurrencyRowItem> listingRowItems) {
        this.context = context;
        this.listingRowItems = listingRowItems;
    }

    @Override
    public int getCount() {
        return listingRowItems.size();
    }

    @Override
    public Object getItem(int position) {
        return listingRowItems.get(position);
    }

    @Override
    public long getItemId(int position) {
        return listingRowItems.indexOf(getItem(position));
    }

    private class ViewHolder {
        TextView currency_name;
        TextView currency_price;
        TextView curency_percent24hr;
        TextView currency_24hrvolume;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;

        LayoutInflater mInflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.currency_row, null);
            holder = new ViewHolder();

            holder.currency_name = (TextView) convertView.findViewById(R.id.crypto_name);
            holder.curency_percent24hr = (TextView) convertView.findViewById(R.id.crypto_percentage_change);
            holder.currency_price= (TextView) convertView.findViewById(R.id.crypto_current_price);
            holder.currency_24hrvolume= (TextView) convertView.findViewById(R.id.crypto_volume);

            CurrencyRowItem row_pos = listingRowItems.get(position);

            holder.currency_name.setText(row_pos.currencyName);
            holder.curency_percent24hr.setText(row_pos.currencyPercentageChange);
            holder.currency_price.setText(row_pos.currencyPrice);
            holder.currency_24hrvolume.setText(row_pos.currency24hrVolume);


            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }
        return convertView;
    }
}

Answer 1

我猜应该是这样的：

cryptoCurrency.jsonCurrencyName.add(jOb.getString("name"));
        cryptoCurrency.jsonCurrencyPercent.add(jOb.getString("percent_change_24h"));
        cryptoCurrency.jsonCurrencyPrice.add(jOb.getString("price_gbp"));
        cryptoCurrency.jsonCurrencyVolume.add(jOb.getString("24h_volume_gbp"));

你没有填充数据，这个数组可能是空的

Answer 2

你的数组是空的。

D/ERROR: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0 

尝试添加这个：

if (returnedJsonArrayResult != null && 
    !returnedJsonArrayResult.isEmpty()) {
    for (int i = 0; ...) {
        // your code
    }
}

另外，循环整数从 0 开始，而不是 1。数组从 0 开始。如果你从一个开始，你总是会跳过第一个条目。