在C＃中类之间的引用？

Question

I'm taking an introduction course in databases, and am working on the first hand-in. One of the questions is to "add a reference in the class User so it can acces a users Organization" I have a User class that looks like this:

 public class User
    {
        [Key]
        public string Username { get; set; }
        public string DisplayName { get; set; }
    }

And my organization class looks like this:

public class Organization
    {
        public int OrganizationId { get; set; }
        public string OrganizationName { get; set; }
    }

I don't understand the question stated by my teacher -- what does it mean to add a reference, when both classes are declared in the same .cs file?

Answer 1

I think the question refers to foreign key. It is something like "User is part of Organization".

Example:

 public class Student
{
    public int StudentID { get; set; }
    public string StudentName { get; set; }

    //Foreign key for Standard
    public int StandardId { get; set; }
    public Standard Standard { get; set; }
}

public class Standard
{
    public int StandardId { get; set; }
    public string StandardName { get; set; }

    public ICollection<Student> Students { get; set; }
}

Please refer to the following page for more information about foreign key in Entity framework: http://www.entityframeworktutorial.net/code-first/foreignkey-dataannotations-attribute-in-code-first.aspx