Get class names of all entities that inherit from a base entity

Question

Assuming i have a base entity class:

public abstract partial class Person
    {
        public Person()
        {
        }

        public string FirstName { get; set; }
        public string LastName { get; set; }


    }

and i have multiple entities that inherit from that entity e.g:

public partial class Customer : Person
{
    public Customer()
    {
    }

    public int CustomerStatusId { get; set; }
    public string AccountNumber { get; set; }

}

and a few more entities that inherit from the Person class.

is there a way i can get all the Entities class names that inherit from the Person class? i would like to display those in a select box, to create a generic AddUser method.

Take a look at this post, I think this is what you need: http://stackoverflow.com/questions/2480691/getting-all-types-from-an-assembly-derived-from-a-base-class — Rob, Nov 12 '13 at 07:42
I *assume* you only want to know about implementations within (the current assembly/a limited set of assemblies) because, of course, this being a public class there could be an infinite number of inheriting classes. — Damien_The_Unbeliever, Nov 12 '13 at 07:45

score 2 · Accepted Answer · edited May 23 '17 at 12:19

2

var names = assembly.GetTypes().Where(t => baseType.IsAssignableFrom(t)).Select(t => t.Name);

Try something like the above to get just the names.

Use the following answer for reference How to find all the types in an Assembly that Inherit from a Specific Type C#

edited May 23 '17 at 12:19

Community

1
1

answered Nov 12 '13 at 07:39

TGH

38,769
12
102
135

This should do it but it appears you have a misplaced return statement. – Nico Nov 12 '13 at 07:44
I agree. I have updated – TGH Nov 12 '13 at 07:45

score 1 · Answer 2 · answered Nov 12 '13 at 07:45

You need to use reflections:

using System.IO;
using System;
using System.Reflection;
using System.Linq;

class Program
{
    static void Main()
    {
        Assembly a = typeof(Program).Assembly;

        var types = a.GetTypes().Where(i=>i.IsSubclassOf(typeof(T)));

        foreach(var i in types)
        {
            Console.WriteLine(i);
        }
    }
}

public class T {  }
public class TT : T {  }
public class TTT : T {  }

haim770 · Answer 3 · 2013-11-12T08:01:24.820

1

Reflection is the easiest way to go (as suggested in other answers).

Yet (since you tagged the question with entity-framework and you mentioned Entities) in case your intent is to get list of derived types that exists in the database (to fill up a lookup) you can try this:

var typeNames = context.Set<Person>()
                       .ToList()
                       .Select(x => x.GetType().Name)
                       .Distinct();

edited Nov 12 '13 at 08:01

answered Nov 12 '13 at 07:51

haim770

48,394
7
105
133

Interesting. i usually try to avoid using reflection, but i wonder which one would be more "costly", my guess would be that another db call would be more then the reflection one. – Rafael Herscovici Nov 12 '13 at 07:53
1

if you mean "costly" in terms of performance, Reflection would probably be much faster, especially if your table contains many `Person`. however, if you require your drop-down list to only contain types that *already exists* in the database, i guess you would have to use that solution. – haim770 Nov 12 '13 at 07:58

Get class names of all entities that inherit from a base entity

3 Answers3