How to check if a class inherits another class without instantiating it?

atoMerz picture atoMerz · Jan 2, 2012 · Viewed 105.9k times · Source

Suppose I have a class that looks like this:

class Derived : // some inheritance stuff here
{
}

I want to check something like this in my code:

Derived is SomeType;

But looks like is operator need Derived to be variable of type Dervied, not Derived itself. I don't want to create an object of type Derived.
How can I make sure Derived inherits SomeType without instantiating it?

P.S. If it helps, I want something like what where keyword does with generics.
EDIT:
Similar to this answer, but it's checking an object. I want to check the class itself.

Answer

Ani picture Ani · Jan 2, 2012

To check for assignability, you can use the Type.IsAssignableFrom method:

typeof(SomeType).IsAssignableFrom(typeof(Derived))

This will work as you expect for type-equality, inheritance-relationships and interface-implementations but not when you are looking for 'assignability' across explicit / implicit conversion operators.

To check for strict inheritance, you can use Type.IsSubclassOf:

typeof(Derived).IsSubclassOf(typeof(SomeType))