Are there Func objects with more than 4 parameters?

Question

I saw here that Func<(Of <(T1, T2, T3, T4, TResult>)>) Delegate was the last Func in the namespace. What do you do if you need more than 4 parameters?

Answer 1

You could create your own Func delegates, or you could wait for .NET 4 to arrive (it includes built-in Func and Action delegates with up to sixteen parameters).

As others have mentioned, if you find yourself needing a delegate that takes this many parameters then maybe it's time to think about some sort of refactoring.

public delegate TResult Func<T1, T2, T3, T4, T5, TResult>
    (T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5);

public delegate TResult Func<T1, T2, T3, T4, T5, T6, TResult>
    (T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6);

public delegate TResult Func<T1, T2, T3, T4, T5, T6, T7, TResult>
    (T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7);

public delegate TResult Func<T1, T2, T3, T4, T5, T6, T7, T8, TResult>
    (T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8);

// etc

Answer 2

Create a parameter object, perhaps?

The refactor catalog has a good description.

Kindness,

Dan

Answer 3

In .Net 4, there's overloads till 17 (give or take) parameters.

Personally, I think that's nuts. If you need more than 4 parameters, then it's time to create a new class that has all the parameters you need as properties.