如何确定类型是否在继承层次结构中

Question

I need to determine if an object has a specific type in it's inheritance hierarchy, however I can't find a good way of doing it.

An very basic example version of my classes are:

Public Class Domain

End Class

Public Class DerivedOne
    Inherits Domain

End Class

Public Class DerivedTwo
    Inherits DerivedOne

End Class

Public Class DerivedThree
    Inherits Domain

End Class

The following does work, however it isn't very elegant in my opinion. Also the more levels of inheritance that get created, the more checks need to be done and it would be easy to forget this piece of code needs to be updated.

If GetType(T) Is GetType(Domain) OrElse _
    GetType(T).BaseType Is GetType(Domain) OrElse _
    GetType(T).BaseType.BaseType Is GetType(Domain) Then

End If

Is there a way of getting 'Is type of Domain anywhere in T's inheritance hierarchy'?

(Answers welcome in C# or VB.NET)

---

UPDATE

One bit of vital information I missed out due to my own idiocy!

T is a Type object (from the class' generic type)

Answer 1

You can use the Type.IsAssignableFrom method.

In VB:

If GetType(Domain).IsAssignableFrom(GetType(DerivedThree)) Then

In C#:

if (typeof(Domain).IsAssignableFrom(typeof(DerivedThree)))

Answer 2

Why is nobody mentioning Type.IsSubclassOf(Type) ?

https://docs.microsoft.com/en-us/dotnet/api/system.type.issubclassof?view=netframework-4.7.2

Careful, it returns false if called for two equal types ;)

Answer 3

I need to determine if an object has a specific type in it's inheritance hierarchy, however I can't find a good way of doing it.

An very basic example version of my classes are:

Public Class Domain

End Class

Public Class DerivedOne
    Inherits Domain

End Class

Public Class DerivedTwo
    Inherits DerivedOne

End Class

Public Class DerivedThree
    Inherits Domain

End Class

The following does work, however it isn't very elegant in my opinion. Also the more levels of inheritance that get created, the more checks need to be done and it would be easy to forget this piece of code needs to be updated.

If GetType(T) Is GetType(Domain) OrElse _
    GetType(T).BaseType Is GetType(Domain) OrElse _
    GetType(T).BaseType.BaseType Is GetType(Domain) Then

End If

Is there a way of getting 'Is type of Domain anywhere in T's inheritance hierarchy'?

(Answers welcome in C# or VB.NET)

---

UPDATE

One bit of vital information I missed out due to my own idiocy!

T is a Type object (from the class' generic type)

Answer 4

How about is operator ?

if(obj is Domain)
{
    // 
}