Object reference not set to an instance of an object

报错信息

NullReferenceException: Object reference not set to an instance of an object TileManage.Start () (at Assets/Scriput/TileManage.cs:65)

原因

List<Goods> goodsList;

    //定义goods的数据类型

    public struct Goods 
    {
        public int goods_id;
        public int grid_x;
        public int grid_y;
    }

    Goods goods1, goods2, goods3;
    List<Goods> goodsList;


    private void Start()
    {
        goods1 = new Goods();
        goods1.goods_id = 0;
        goods1.grid_x = 2;
        goods1.grid_y = 2;


        goods2 = new Goods();
        goods2.goods_id = 1;
        goods2.grid_x = 2;
        goods2.grid_y = 2;

        goods3 = new Goods();
        goods3.goods_id = 2;
        goods3.grid_x = 1;
        goods3.grid_y = 1;

        goodsList.Add(goods1);
        goodsList.Add(goods2);
        goodsList.Add(goods3);

        print(goodsList);
    }

解决方法

List<Goods> goodsList;

改为

List<Goods> goodsList = new List<Goods>();