ListView里有Button和EditText是记录EditText状态

　　项目里要做点菜的功能，大概是两个Button中间一个EditText，点击可以改变EditText内容，问题是，当页面跳转之后再返回时，记不住EditText的状态，参考了

http://blog.sina.com.cn/s/blog_65570a20010108lp.html 自己实现了记住点了几份菜的信息。代码如下，用一个HashMap去记录状态，Adapter如下

/**
 * @author ypeng
 *  
 */
public class DishAdapter extends BaseAdapter {

    private Activity context;
    private List<BooK> dishlist;
    // 用来记录所有ListView记录对应EditText的状态
    public HashMap<Integer, String> isChanged;

    public DishAdapter(Activity context, List<BooK> dishlist) {
        this.context = context;
        this.dishlist = dishlist;
        init();
    }

    public HashMap<Integer, String> getIsChanged() {
        return isChanged;
    }

    private void init() {
        isChanged = new HashMap<Integer, String>();
        for (int i = 0; i < dishlist.size(); i++) {
            isChanged.put(i, "0");
        }
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return dishlist.size();
    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return dishlist.get(position);
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        convertView = LayoutInflater.from(context).inflate(R.layout.menu_item,
                null);
        TextView resName;// 菜品名称
        TextView resPrice;// 菜品单价
        TextView resDiscount;// 折扣
        Button addnum;// 加一份
        Button minusnum;// 减一份
        final EditText resNum;// 点几份
        resName = (TextView) convertView.findViewById(R.id.menu_item_dishname);
        resPrice = (TextView) convertView
                .findViewById(R.id.menu_item_dishprice);
        resDiscount = (TextView) convertView
                .findViewById(R.id.menu_item_dishdiscount);
        resNum = (EditText) convertView.findViewById(R.id.dishnum);
        addnum = (Button) convertView.findViewById(R.id.OneDish);
        minusnum = (Button) convertView.findViewById(R.id.MoreDish);

        String name = dishlist.get(position).getName();
        double price = dishlist.get(position).getPrice();
        double discount = dishlist.get(position).getDiscount();

        resName.setText(name);
        resPrice.setText(Double.toString(price));
        resDiscount.setText(Double.toString(discount));
        addnum.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                int num = Integer.valueOf(resNum.getText().toString());
                num++;
                resNum.setText(Integer.toString(num));
                dishlist.get(position).setNum(num);
                isChanged.put(position, Integer.toString(num));
            }
        });
        minusnum.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                int num = Integer.valueOf(resNum.getText().toString());
                if (num > 0) {
                    num--;
                    resNum.setText(Integer.toString(num));
                    dishlist.get(position).setNum(num);
                    isChanged.put(position, Integer.toString(num));
                }
                if (num == 0) {// 必须判断，不判断出错
                    resNum.setText(Integer.toString(0));
                    dishlist.get(position).setNum(num);
                    isChanged.put(position, Integer.toString(num));

                }
            }
        });
        resNum.setText(isChanged.get(position));
        return convertView;

    }

}