Pass Method as Parameter using C#

Question

I have several methods all with the same parameter types and return values but different names and blocks. I want to pass the name of the method to run to another method tha

Answer 1

You need to use a delegate. In this case all your methods take a string parameter and return an int - this is most simply represented by the Func delegate¹. So your code can become correct with as simple a change as this:

public bool RunTheMethod(Func myMethodName)
{
    // ... do stuff
    int i = myMethodName("My String");
    // ... do more stuff
    return true;
}

Delegates have a lot more power than this, admittedly. For example, with C# you can create a delegate from a lambda expression, so you could invoke your method this way:

RunTheMethod(x => x.Length);

That will create an anonymous function like this:

// The <> in the name make it "unspeakable" - you can't refer to this method directly
// in your own code.
private static int <>_HiddenMethod_<>(string x)
{
    return x.Length;
}

and then pass that delegate to the RunTheMethod method.

You can use delegates for event subscriptions, asynchronous execution, callbacks - all kinds of things. It's well worth reading up on them, particularly if you want to use LINQ. I have an article which is mostly about the differences between delegates and events, but you may find it useful anyway.

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¹ This is just based on the generic Func delegate type in the framework; you could easily declare your own:

public delegate int MyDelegateType(string value)

and then make the parameter be of type MyDelegateType instead.