C#.NET - How can I get typeof() to work with inheritance?

Question

I will start by explaining my scenario in code:

public class A { }

public class B : A { }

public class C : B { }

public class D { }

public c         


        

Answer 1

For VB.NET with Visual Studio 2008, you can check it like:

'MyTextBox control is inherited by Textbox
If Ctl.GetType.Name = "MyTextBox" then    

End If

Answer 2

As an alternative to the (c is B) check, you can also do the following:

var maybeB = c as B;
if (maybeB != null) {
   // make use of maybeB
}

This is preferred in some cases since in order to make use of c as a B when using is, you would have to cast anyway.

Answer 3

You can just use is:

if (c is B) // Will be true

if (d is B) // Will be false

Answer 4

This looks like a job for polymorphism, as opposed to a big switch statement with tests for specific classes.

Answer 5

typeof(B).IsInstanceOfType(c)

Similar to the answer above from sam-harwell, sometimes you may have the type "B" in a variable, so you need to use reflection rather than the "is" operator.

I used Sam's solution, and was pleasantly surprised when Resharper made this suggestion.

Answer 6

Edit: this answers the question in the thread title. cdm9002 has the better answer to the problem as described in the full post.

typeof(B).IsAssignableFrom(c.GetType())