Func delegate with no return type

Question

Rewritten: All of the Func delegates return a value. What are the .NET delegates that can be used with methods that return void?

Answer 1

Try System.Func<T> and System.Action

Answer 2

...takes no arguments and has a void return type?

I believe "Action" is a solution to this.

Answer 3

All of the Func delegates take at least one parameter

That's not true. They all take at least one type argument, but that argument determines the return type.

So Func<T> accepts no parameters and returns a value. Use Action or Action<T> when you don't want to return a value.

Answer 4

All Func delegates return something; all the Action delegates return void.

Func<TResult> takes no arguments and returns TArgument:

public delegate TResult Func<TResult>()

Action<T> takes one argument and does not return a value:

public delegate void Action<T>(T obj)

Action is the simplest, 'bare' delegate:

public delegate void Action()

There's also Func<TArg1, TResult> and Action<TArg1, TArg2> (and others up to four arguments). All of these (except for Action<T>) are new to .NET 3.5 (defined in System.Core).