How to do a static cast in C#?

Question

Given a couple types like this:

interface I {}
class C : I {}

How can I do a static type cast? By this I mean: how can I change its type in

Answer 1

If you're really just looking for a way to see if an object implements a specific type, you should use as.

I i = whatever as i;
if (i == null) // It wasn't

Otherwise, you just cast it. (There aren't really multiple types of casting in .NET like there are in C++ -- unless you get deeper than most people need to, but then it's more about WeakReference and such things.)

I i = (I)c;

If you're just looking for a convenient way to turn anything implementing I into an I, then you could use an extension method or something similar.

public static I ToI(this I @this)
{
    return @this;
}