在原来的列表，使用C＃为什么名单的副本仍然更改属性 [英] Why does copy of the List still change properties in the original List using C#

问题描述

可以说我有这个类

public class Employee
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public bool isActive { get; set; }
}

和使用这样的：

    List<Employee> Employees = new List<Employee>();
    Employees.Add(new Employee { FirstName = "firstname", LastName = "lastname", isActive = true });
    List<Employee> EmployeesCopy = new List<Employee>(Employees);
    EmployeesCopy[0].isActive = false;

为什么在 EmployeesCopy 的 isActive 属性还修改属性在原始列表改变？

Why does change in isActive property of EmployeesCopy also modify property in the original list?

推荐答案

由于新的列表仍旧引用同一个Employee对象。你可以做这样的事情创建新的一个新的列表：

Because the new list still contains references to the same employee objects. You can create new ones in a new list by doing something like this:

    List<Employee> Employees = new List<Employee>();
    Employees.Add(new Employee { FirstName = "firstname", LastName = "lastname", isActive = true });
    List<Employee> EmployeesCopy = Employees.Select(x => new Employee(x)).ToList();

    public class Employee
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public bool isActive { get; set; }

        public Employee()
        { }

        public Employee(Employee e)
        {
            FirstName = e.FirstName;
            LastName = e.LastName;
            isActive = e.isActive;
        }
    }

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