Passing a function as parameter

Question

I need a way to define a method in c# like this:

public String myMethod(Function f1,Function f2)
{
    //code
}

Let f1 is:

public String f1(String s1, String s2)
{
    //code
}

is there any way to do this?

Answer 1

Sure you can use the Func<T1, T2, TResult> delegate:

public String myMethod(
    Func<string, string, string> f1,
    Func<string, string, string> f2)
{
    //code
}

This delegate defines a function which takes two string parameters and return a string. It has numerous cousins to define functions which take different numbers of parameters. To call myMethod with another method, you can simply pass in the name of the method, for example:

public String doSomething(String s1, String s2) { ... }
public String doSomethingElse(String s1, String s2) { ... }

public String myMethod(
    Func<string, string, string> f1,
    Func<string, string, string> f2)
{
    //code
    string result1 = f1("foo", "bar");
    string result2 = f2("bar", "baz");
    //code
}
...

myMethod(doSomething, doSomethingElse);

Of course, if the parameter and return types of f2 aren't exactly the same, you may need to adjust the method signature accordingly.