How to find all direct subclasses of a class with .NET Reflection

Question

Consider the following classes hierarchy: base class A, classes B and C inherited from A and class D inherited from B.

public class A     {...}
public class B : A {...}
public class C : A {...}
public class D : B {...}

I can use following code to find all subclasses of A including D:

var baseType = typeof(A);
var assembly = typeof(A).Assembly;
var types = assembly.GetTypes().Where(t => t.IsSubclassOf(baseType));

But I need to find only direct subclasses of A (B and C in example) and exclude all classes not directly inherited from A (such as D). Any idea how to do that?

Answer 1

For each of those types, check if

type.BaseType == typeof(A) 

Or, you can put it directly inline:

var types = assembly.GetTypes().Where(t => t.BaseType == typeof(baseType)); 

Answer 2

Use Type.BaseType for that. From the documentation:

The base type is the type from which the current type directly inherits. Object is the only type that does not have a base type, therefore null is returned as the base type of Object.

Answer 3

Just compare them appropriately:

var types = assembly.GetTypes().Where(t => t.BaseType == baseType);