List 为什么Add值就报错？

[nemocc]

总是一到 bill.item.Add(billitem);这里就报“未将对象引用设置到对象的实例”。
代码如下：
public class StoreBill
{
/// <summary>
/// ID
///// </summary>
public int ID { get; set; }
/// <summary>
/// 商品集合
/// </summary>
private List<StoreBillItem> _Items = new List<StoreBillItem>();
public List<StoreBillItem> item { get; set; }
}

谢谢各位了！


Goods gd = new Goods();
StoreBill bill = new StoreBill();
StoreBillItem billitem = new StoreBillItem();

for (int i = 0; i < gridView1.RowCount; i++)
{

gd.ID = int.Parse(i.ToString() + "123");
gd.Code = gridView1.GetRowCellValue(i, "Code").ToString();
gd.Name = gridView1.GetRowCellValue(i, "Name").ToString();
gd.Scole = int.Parse(gridView1.GetRowCellValue(i, "Scole").ToString());
gd.Price = decimal.Parse(gridView1.GetRowCellValue(i, "Price").ToString());



billitem.ID = int.Parse(i.ToString() + "456");
billitem.Code = gridView1.GetRowCellValue(i, "Code").ToString();
billitem.Name = gridView1.GetRowCellValue(i, "Name").ToString();
billitem.Scole = int.Parse(gridView1.GetRowCellValue(i, "Scole").ToString());
billitem.Price = decimal.Parse(gridView1.GetRowCellValue(i, "Price").ToString());
bill.item.Add(billitem);
}

[事理]

for (int i = 0; i < gridView1.RowCount; i++) { StoreBillItem billitem = new StoreBillItem();

[nemocc]

引用 1 楼 slyzly 的回复:

for (int i = 0; i < gridView1.RowCount; i++) { StoreBillItem billitem = new StoreBillItem();

放在里面吗？

[娃都会打酱油了]

你的item又没用那个带下划线的私有字段，那个倒是new了的，然后get set的呢没有实例化，当然报异常了

[nemocc]

引用 3 楼 starfd 的回复:

你的item又没用那个带下划线的私有字段，那个倒是new了的，然后get set的呢没有实例化，当然报异常了

谢谢版主大人，我忘记贴代码了， public class StoreBillItem { public int ID { get; set; } /// <summary> /// 商品编码 /// </summary> public string Code { get; set; } public string Name { get; set; } public int Scole { get; set; } public decimal Price { get; set; }

[wjq]

private List<StoreBillItem> _Items = new List<StoreBillItem>(); public List<StoreBillItem> item { get{return _Items;} }

[nemocc]

引用 5 楼 wjq 的回复:

private List<StoreBillItem> _Items = new List<StoreBillItem>(); public List<StoreBillItem> item { get{return _Items;} }

及时结帖！谢谢了！

[lc_ant]

private List<StoreBillItem> _Items = new List<StoreBillItem>(); public List<StoreBillItem> item { get{return _Items;} }