CODEWITHSUNDEEP
c#
user12857295
user12857295

Reputation:

Pass any method of an object as a paramter in a function

The title is may be not clear enough, but I'll show you a short program in order to make you understand what I want to do:

Class Program
{
   private static Obj A = new Obj(...);

   private static void Function(AnyMethodOfMyObject() m)
   {
      object[] result = A.m();
      ...
   }

   static void main()
   {
      double a,b,c = 0;
      string d = " ";
      Function(MethodX(a,b,c));
      Function(MethodY(d,a,b));
      ...

   }
}

The methods will always return the same type which is an object[], but I don't have the same number/type of argument.

Thanks !

Upvotes: 0

Views: 87

Answers (1)

canton7
canton7

Reputation: 42350

You can do this simply with a Func<object[]>:

class Program
{
   private static Obj A = new Obj(...);

   private static void Function(Func<object[]> m)
   {
      object[] result = m();
      ...
   }

   static void main()
   {
      double a,b,c = 0;
      string d = " ";
      Function(() => A.MethodX(a,b,c));
      Function(() => A.MethodY(d,a,b));
      ...

   }
}

Func<object[]> is a delegate (broadly, a reference to a method) which does not take any parameters, and which returns an array of objects. While MethodX takes 3 parameters (a,b,c), we can create a new anonymous method without doesn't take any parameters itself, and which just calls MethodX and passes in the values of a, b and c (they're captured at the point that we create this new anonymous method). This is what () => MethodX(a, b, c) does.

If you have different Obj instances and you want to control which one the method is called on, then use a Func<Obj, object[]>. This takes an Obj as a parameter, and returns an object[] as before.

class Program
{
   private static Obj A = new Obj(...);

   private static void Function(Func<Obj, object[]> m)
   {
      object[] result = m(A);
      ...
   }

   static void main()
   {
      double a,b,c = 0;
      string d = " ";
      Function(x => x.MethodX(a,b,c));
      Function(x => x.MethodY(d,a,b));
      ...

   }
}

Upvotes: 1

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