C# Multiple Inheritance

Question

Currently im studying the C# with ASP.NET MVC 4 with Code First Approach. Im Visual Basic Developer, and Now i want to Start C#. And, now i came accross the situation where i've to manage Multiple Inheritance. But, it is not possible with Class i thought. So, how should i manage these classes i have :

//I have the Following Person Class which Hold Common Properties 
//and a Type of Person e.g : Student, Faculty, Administrative
public class Person
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Type { get; set; }
}


//This is my Student Class, which is Derived from Person
public class Student : Person
{
    public DateTime DateOfBirth { get; set; }
    public DateTime EnrollmentDate { get; set; }
    public string Remarks { get; set; }

    public bool Approved { get; set; }
    public DateTime ApprovedDate { get; set; }
    public int ApprovedUserId { get; set; }
}


//This is my Faculty Class, which is also Derived from Person
public class Faculty : Person
{
    public DateTime HiredDate { get; set; }

    public bool Approved { get; set; }
    public DateTime ApprovedDate { get; set; }
    public int ApprovedUserId { get; set; }
}

What I want to Make is Approved, ApprovedDate, and ApprovedUserId also common. I want to Specify those Properties like :

 public class Approve {
    public bool Approved { get; set; }
    public DateTime ApprovedDate { get; set; }
    public int ApprovedUserId { get; set; }
}

And, want to use like :

public class Student : Person, Approve
{
    public DateTime DateOfBirth { get; set; }
    public DateTime EnrollmentDate { get; set; }
    public string Remarks { get; set; }
}

And, i cannot put those things inside PERSON. Because, i've to use this to another classes to, but those are not Person.

Then, how do i achieve this...

Please give me an Example for the Above Situation.

Please Help. And, Thank You so much in Advance.

Answer 1

One possible solution would be to modify your hierarchy:

public class PersonWithApprove : Person { // TODO: replace with non disgusting name
    public bool Approved { get; set; }
    // etc...
}

public class Student : PersonWithApprove {
}

public class Faculty : PersonWithApprove {
}

Or you could create an interface:

public interface IApprove {
    bool Approved { get; set; }
    // etc
}

public class Student : Person, IApprove {
}

You might also leave the class Approve as such, and have classes with a property of that type:

public class Student : Person {
    Approve _approve = new Approve();
    public Approve Approve {
        get { return _approve; }
    }
}

Answer 2

It's a good case, IMHO, to use interfaces here, something like that:

  // Interfaces:

  // General person
  public interface IPerson {
    int Id { get; set; }
    string FirstName { get; set; }
    string LastName { get; set; }
    string Type { get; set; }
  }

  // Approvable person
  public interface IApprovable {
    bool Approved { get; set; }
    DateTime ApprovedDate { get; set; }
    int ApprovedUserId { get; set; }
  } 

  // Student is a IPerson + IApprovable
  public interface IStudent: IPerson, IApprovable {
    DateTime DateOfBirth { get; set; }
    DateTime EnrollmentDate { get; set; }
  }

  // So classes will be

  public class Approve: IApprovable {
    ... //TODO: Implement IApprovable interface here
  } 

  public class Faculty: IPerson, IApprovable {
    public DateTime HiredDate { get; set; }

    ... //TODO: Implement IPerson interface here
    ... //TODO: Implement IApprovable interface here
  }

  public class Student: IStudent {
    public string Remarks { get; set; }

    ... //TODO: Implement IStudent interface here
  }