如何将项目添加到列表

Question

我有班级的人，城市和街道。编号它的门牌号。我面临这样一个问题，即一个人不仅可以住在 1 个城市，还可以住在 2 个（纽约和洛杉矶）。如何向人添加新城市。

var live = new List<Live>();

    lives.Add(new Live

    {

        Person = new Person

        {

            FirstName = "Joe",

            LastName = "Doe"

        },

        City = new City

        {

            Name = "NY",

        },

        Number = 31

    });

Answer 1

在Live课堂上，将变量设为Citya City[]，允许某人居住在多个城市。City City;到City[] Cities;然后你可以改变你的代码看起来有点像这样......var live = new List<Live>();lives.Add(new Live{&nbsp; &nbsp; Person = new Person&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; FirstName = "Joe",&nbsp; &nbsp; &nbsp; &nbsp; LastName = "Doe"&nbsp; &nbsp; },&nbsp; &nbsp; Cities = new City[]&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; new City {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Name = "LA"&nbsp; &nbsp; &nbsp; &nbsp; },&nbsp; &nbsp; &nbsp; &nbsp; new City {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Name = "NY"&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; },&nbsp; &nbsp; Number = 31});编辑：如果你想Cities成为一个List<City>那么你可以修改你的代码看起来像这样......var live = new List<Live>();lives.Add(new Live{&nbsp; &nbsp; Person = new Person&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; FirstName = "Joe",&nbsp; &nbsp; &nbsp; &nbsp; LastName = "Doe"&nbsp; &nbsp; },&nbsp; &nbsp; Cities = new List<City>(&nbsp; &nbsp; new City[]&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; new City {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Name = "LA"&nbsp; &nbsp; &nbsp; &nbsp; },&nbsp; &nbsp; &nbsp; &nbsp; new City {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Name = "NY"&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }),&nbsp; &nbsp; Number = 31});

Answer 2

您可以将 City 改为 Cities （城市列表）。var live = new List<Live>();lives.Add(new Live{&nbsp; &nbsp; Person = new Person&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; FirstName = "Joe",&nbsp; &nbsp; &nbsp; &nbsp; LastName = "Doe"&nbsp; &nbsp; },&nbsp; &nbsp; Cities = new List<City>&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; new City&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Name = "NY",&nbsp; &nbsp; &nbsp; &nbsp; },&nbsp; &nbsp; &nbsp; &nbsp; new City&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Name = "LA",&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; },&nbsp; &nbsp; Number = 31});为了编译，你的 Person 类应该像这样定义：public class Live{&nbsp; &nbsp; public Person Person { get; set; }&nbsp; &nbsp; public List<City> Cities { get; set; }&nbsp; &nbsp; public int Number;}另外，根据您的评论，如果您想要Number每个城市，那么我能想象的最简单的解决方案是将 Number 从 Person 类移动到 City 类。最终，这取决于您需要准确建模的内容，还有其他方法。