如何将类中的信息添加到列表中

本文关键字：添加 列表 信息 | 更新日期: 2023-09-27 18:27:20

如果我有两个这样的类：

public class Department
{
    public int Id { get; set; }
    public string Name { get; set; }
    public List<Employee> employees { get; set; }
}
public class Employee
{
    public string Name { get; set; }
    public string Job { get; set; }
    public string Date { get; set; }
}

然后如果我这样做：

var departments = new List<Department>();
Department d = new Department
{
    Id = 1,
    Name = "Depart1",
 };
Department d2 = new Department
{
    Id = 2,
    Name = "Depart2",
 };
 departments.Add(d);
departments.Add(d2);

如何使用foreach循环将添加到Department类中的员工列表？当我这样做时：

foreach(Department dmt in departments)
{
    Employee worker = new Employee 
    {
        Name = "Steve",
        Job = "Cleanup",
        Date = "Today",
     };
     dmt.employees.Add(worker );
}

我没有得到任何构建错误，但没有添加任何内容。有什么建议吗？

如何将类中的信息添加到列表中

您没有实例化employees属性。将您的类定义更改为：

public class Department
{
    public int Id { get; set; }
    public string Name { get; set; }
    public List<Employee> employees { get; set; }
    public Department()
    {
        employees = new List<Employee> ();
    }
}

或者，如果您不想使用构造函数来实例化employees属性，那么在尝试将Employee对象添加到List<Employee>之前，您只需要确保这样做。

您需要在Department类中初始化公共属性员工
在这种情况下，您可以在Department实例的构造函数中执行此操作。

public class Department 
{ 
    public int Id { get; set; } 
    public string Name { get; set; } 
    public List<Employee> employees { get; set; } 
    public Department()
    {
        employees = new List<Employee>();
    }
}

像这样尝试

public class Department 
{ 
    public int Id { get; set; } 
    public string Name { get; set; } 
    public List<Employee> employees { get; set; } 
    public Department()
    {
        employees = new List<Employee>();
    }
} 
foreach(Department dmt in departments)
{
    dmt.employees.Add( new Employee () {
        // InterestedID = ((int)dataReader["JobId"]),
        Name = "Steve",
        Job = "Cleanup",
        Date = "Today",
     });   
}

我会这样设计我的类，使Employees List只读：

public class Department 
{
  private readonly List<Employee> _employees = new List<Employee>();
  public int Id { get; set; }     
  public string Name { get; set; }     
  public List<Employee> employees { get { return this._employees; }}       
}
相关文章：