c# - 返回列表中对象的正确方法

Question

当我尝试返回填充对象的卡丁车列表时，我得到“systems.collections.generic.list”如何以正确的方式返回卡丁车？

方法

    public class AddToKart
    {
        public static List<KartItem> PutItemInKart(string input, int inputNumber, double inputPrice)
        {
            List<KartItem> kart = new List<KartItem>();
            kart.Add(new KartItem() {
                Item = input,
                Pound = inputNumber,
                Cost = inputPrice
            });;
            return kart;
        }
    }

对象检索数据

 public class KartItem
    {
        public string Item { get; set; }
        public int Pound { get; set; }
        public double Cost { get; set; }

        public KartItem(string item, int pound, double cost)
        {
            Item = item;
            Pound = pound;
            Cost = cost;
        }
        public KartItem()
        {
        }
    }

测试方法 PutItemInKart 测试项目磅数和成本来自对象。

  [Fact]
        public void AddToKartMethodItem()
        {
            //Arrange
            string expected = "fdfdfsds";

            //Act
            List<KartItem> items = AddToKart.PutItemInKart(expected, 3, 4.5);
            string actual = items[0].Item;

            //Assert
            Assert.Equal(expected, actual);
        }
        [Fact]
        public void AddKartMethodPound()
        {
            int expected = 3;
            List<KartItem> numbers = AddToKart.PutItemInKart("mingt", expected, 4.45);
            int actual = numbers[0].Pound;
            Assert.Equal(expected, actual);
        }
        [Fact]
        public void AddToKartMethodCost()
        {
            double expected = 34.56;
            List<KartItem> cost = AddToKart.PutItemInKart("fdsf", 5, expected);
            double actual = cost[0].Cost;
            Assert.Equal(expected, actual);
        }

Answer 1

这取决于您使用的场景。从您的代码中我可以看出您必须有一个 KartContainer 类，它必须包含所有与卡丁车相关的操作。

    public class KartContainer
    {
        private List<KartItem> Items = new List<KartItem>();

        public void AddItem(KartItem item)
        {
            Items.Add(KartItem);
        }

        public List<KartItem> GetItems()
        {
            return Items;
        }
    }

And you can use it as the following:

        KartContainer kart = new KartContainer();

        KartItem item = new KartItem()
        {
            Item = "",
            Pound = 1,
            Cost = 1
        }

        kart.AddItem(item);
        List<KartItem> Items = kart.GetItems();

UPDATE: After your post update I would like to draw your attention about constructor definition, you must assign constructor parameters to local variables not the opposite.

    public KartItem(string item, int pound, double cost)
    {
        Item = item;
        Pound= pound;
        Cost = cost;
    }