Question

Is there a way to send a any method as a parameter? I need to do it for all kind of method, not caring about signatures and returns. Say something like this (bad code, just for the idea):

public class Foo
{
...
void TestMethod(DontKnowWhatToPutHere theDelegate) {}
...
}

...

foo.TestMethod(-foo.AnotherMethod(1,2)-);
foo.TestMethod(-foo.AnotherMethod("I don't care method signature nor returning type")-);

I tried with no success to do it with Action as parameter.

What I need to do is to send any method to a function, and then use reflection to get method name and parameters, so if there’s another way you guys can figure out, I would gladly hear about it too.

Answer 1

No. The compiler always has to be able to identify a specific delegate to convert to, and there’s no single delegate type which is compatible with all method signatures. You can get a long way by using Action, Action<T>, Action<T1, T2> etc, then Func<TResult>, Func<T1, TResult> etc… but even that’s going to fail when it comes to out and ref parameters. Additionally, there’s overload resolution to consider.

Additionally, your syntax is passing the result of a method invocation, which isn’t the same thing as passing a method in the first place. (That’s ignoring the - prefix/suffix, which appears to be made-up syntax.)

What you could use is Expression<Action> and wrap the method call:

void TestMethod(Expression<Action> action)
{
    ...
}

Then:

foo.TestMethod(() => foo.AnotherMethod(1,2));

Within TestMethod you can then look into the expression tree to find out that it’s a method call, work out the target, the parameters etc. See the MSDN page on expression trees for more information.