C# interface method - generic vs object parameter

[Jim Spector]

Sounds like you are implementing a virtual method table.

Virtual method table - Wikipedia

So to do it in C# you would have e.g. a dictionary<string, action> and dispatch the call thusly: dict[param]()

To make it testable, DI friendly you would encapsulate this logic in a class / interface with e.g. registerhandler(string, action) and execute(string) methods etc.

[BlueSharp]

Thanks for the reply.

I just thought of another idea...

How about using different classes to represent the different actions that the switch statement might have executed. I think that's what is known as "Replace Conditional With Polymorphism".

Replace Conditional with Polymorphism

Is that what you meant by Dependency Injection? Only problem I see is that it might lead to a lot of small classes. Maybe I could put them all in one file to save bloating out the solution?

Yes that is the same concept. Lots of small files make implementing the same interface sticks to SOLID principles. If you start with the unit testing for the method and class you will quickly know if this is over kill or required due to the complexity of the case statement.

[jamsandwich]

Personally I would avoid the switch statement and consider alternatives first you could use Dependency Injection to inject the behaviour of the method when the object is instantiated or pass the behaviour in using Func. But option 2 seems cleaner, instead of an object I would declare the method with an interface in param.


.net - Pass Method as Parameter using C# - Stack Overflow

Thanks for the reply.

I just thought of another idea...

How about using different classes to represent the different actions that the switch statement might have executed. I think that's what is known as "Replace Conditional With Polymorphism".

Replace Conditional with Polymorphism

Is that what you meant by Dependency Injection? Only problem I see is that it might lead to a lot of small classes. Maybe I could put them all in one file to save bloating out the solution?

[BlueSharp]

If I want to create a C# interface with a general "DoProcessing" method that then calls other methods depending on the argument(s) passed in, which is better:

1) Generics, for example:

interface IMyInterface<T>
{
void DoProcessing(T myParam1, string myParam2)
{
// Maybe have a switch statement here to call various methods depending on what value myParam2 has.
}
}

2) Object parameter, for example:

interface IMyInterface
{
void DoProcessing(object myParam1, string myParam2);
{
// Maybe have a switch statement here to call various methods depending on what value myParam2 has.
}
}

For both of the above, the second parameter (myParam2) might be a method name or enum for some kind of state (e.g. "busy", "idle", "blocked").

Personally I would avoid the switch statement and consider alternatives first you could use Dependency Injection to inject the behaviour of the method when the object is instantiated or pass the behaviour in using Func. But option 2 seems cleaner, instead of an object I would declare the method with an interface in param.


.net - Pass Method as Parameter using C# - Stack Overflow

[jamsandwich]

If I want to create a C# interface with a general "DoProcessing" method that then calls other methods depending on the argument(s) passed in, which is better:

1) Generics, for example:

interface IMyInterface<T>
{
void DoProcessing(T myParam1, string myParam2)
{
// Maybe have a switch statement here to call various methods depending on what value myParam2 has.
}
}

2) Object parameter, for example:

interface IMyInterface
{
void DoProcessing(object myParam1, string myParam2);
{
// Maybe have a switch statement here to call various methods depending on what value myParam2 has.
}
}


For both of the above, the second parameter (myParam2) might be a method name or enum for some kind of state (e.g. "busy", "idle", "blocked").