java - ArrayList 无法设置

Question

我有一个用于一个 ListView 的适配器，包含这些

    final ViewHolder holder;
if (convertView == null) 
{
    view = mInflater.inflate(R.layout.auction_list_item, parent , false);
    holder = new ViewHolder();
    holder.image = (ImageView) view.findViewById(R.id.auction_picture_imageView);
    holder.name = (TextView) view.findViewById(R.id.auction_name);
    holder.seller = (TextView) view.findViewById(R.id.auction_seller);
    holder.time = (TextView) view.findViewById(R.id.auction_time);
    holder.duration = (TextView) view.findViewById(R.id.auction_duration);
    holder.currentbid = (TextView) view.findViewById(R.id.auction_currentbid);
    holder.buynow = (TextView) view.findViewById(R.id.auction_buynow);
    holder.layout = (LinearLayout) view.findViewById(R.id.auction_item);
    holder.buynowtext = (TextView) view.findViewById(R.id.auction_buynow_textView);

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

String aucend = auctionList.get(position).get(TAG_AUCTIONENDTIME);
Integer timeSecond = Integer.parseInt(aucend.substring(17, 19));
Integer timeMinute = Integer.parseInt(aucend.substring(14, 16));
Integer timeHour = Integer.parseInt(aucend.substring(11, 13));
Integer timeDay = Integer.parseInt(aucend.substring(0, 2));
Integer timeMonth = Integer.parseInt(aucend.substring(3, 5)) - 1;
Integer timeYear = Integer.parseInt(aucend.substring(6, 10));

Time future = new Time();
future.set(timeSecond, timeMinute, timeHour, timeDay, timeMonth, timeYear);
future.normalize(true);
Long futureMillis = future.toMillis(true);

Long interval = futureMillis - nowMillis;

periods.add(interval);              
Durations.add(holder.duration);
total = total + 1 ;         

我正在尝试插入 holder.duration进入ArrayList<TextView> Durations ，这样我就可以使用一个倒计时器来管理它，使用这个

Durations.add(holder.duration);

这会导致空指针异常。同样的事情也发生在 arraylist 时期。为什么会发生这种情况？

用于存储这些的数组列表在外部初始化

public ArrayList<TextView> Durations;
public ArrayList<Long> periods;

Answer 1

当我没有初始化 arrayList 时，就发生了这种情况。试试这个...

public ArrayList<TextView> Durations = new ArrayList<TextView>();
public ArrayList<Long> periods = new ArrayList<Long>();