Is it possible to declare a method as a parameter in C#?

Question

For example the main method I want to call is this:

public static void MasterMethod(string Input){
    /*Do some big operation*/
}

Usually, I would do something like this this:

public static void StringSelection(int a)
{
    if(a == 1)
    {
       return "if";
    }
    else
    {
       return "else";
    }
}

MasterMethod(StringSelection(2));

But I want to do something like this:

MasterMethod( a = 2
     {
        if(a == 1)
        {
           return "if";
        }
        else
        {
           return "else";
        }
     });

Where 2 is somehow passed into the operation as an input.

Is this possible? Does this have a name?

EDIT:: Please note, the MasterMethod is an API call. I cannot change the parameters for it. I accidentally made a typo on this.

Note: You have a void method returning a string - which won't compile. My answer switches that around. — Reed Copsey, Sep 22 '09 at 16:51

score 21 · Answer 1 · answered Sep 22 '09 at 16:48

21

You can do this via delegates in C#:

public static string MasterMethod(int param, Func<int,string> function)
{
    return function(param);
}


// Call via:
string result = MasterMethod(2, a => 
{
    if(a == 1)
    {
       return "if";
    }
    else
    {
       return "else";
    }
 });

answered Sep 22 '09 at 16:48

Reed Copsey

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Of course, this only makes sense if the 2 is in a variable, not a literal. :-) – Steven Sudit Sep 22 '09 at 16:59
Yeah, of course - just matching the code to the question [Was: MasterMethod(StringSelection(2));] – Reed Copsey Sep 22 '09 at 17:18

score 3 · Answer 2 · answered Sep 22 '09 at 16:48

You can do this with anon delegates:

    delegate string CreateString();

    public static void MasterMethod(CreateString fn)
    {
        string something = fn();
        /*Do some big operation*/
    }

    public static void StringSelection(int a)
    {
        if(a == 1)
        {
           return "if";
        }
        else
        {
           return "else";
        }
    }

    MasterMethod(delegate() { return StringSelection(2); });

score 2 · Answer 3 · edited May 23 '17 at 11:55

2

anonymous methods

edited May 23 '17 at 11:55

Community

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1

answered Sep 22 '09 at 16:47

dove

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@Steven i'd edit but think the answer's fairly well covered elsewhere already. – dove Sep 22 '09 at 16:52

score 2 · Answer 4 · answered Sep 22 '09 at 16:47

2

Yes, use a delegate. Which include Lambda Expressions and anonymous methods

answered Sep 22 '09 at 16:47

Chuck Conway

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score 1 · Answer 5 · answered Sep 22 '09 at 16:48

1

I think you're looking for a delegate.

answered Sep 22 '09 at 16:48

Sterno

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Is it possible to declare a method as a parameter in C#?

5 Answers5