Generic Delegate

Generic Delagates

Next I am planning to give a brief introduction about general purpose generic delegate in C# 3.0.  They are,

Func<>, Action<>, Predicate<>.

But before that I will explain what a generic delegate means. I will begin with an example. Hope readers is aware about the basics of generics.

public delegate TResult MyGenericDelagete<in T1,in T2,out TResult>(T1 arg1,T2 arg2);

Here MyGenericDelagete is a generic delegate which accepts two input parameters and returns something. Input parameters are generic , means it can accept any type but once specified a type then it’s type safe. For example if I create type of this delegate as

MyGenericDelagete<int,int,string> mydel

Now I can point only method which accepts two input parameters of type “int” and return “string”. So the entire code looks like,

public delegate TResult MyGenericDelagete<in T1,in T2,out TResult>(T1 arg1,T2 arg2);

      

        static void Main(string[] args)

        {

            MyGenericDelagete<int, int, string> mydel = MyMethod;

            Console.WriteLine(mydel(100,200));

            Console.ReadKey();

        }

        public static string MyMethod(int a, int b)

        {

            return Convert.ToString(a + b);

        }

I am going to write lambda for the same,

public delegate TResult MyGenericDelagete<in T1,in T2,out TResult>(T1 arg1,T2 arg2);

      

        static void Main(string[] args)

        {

            MyGenericDelagete<int, int, string> mydel = (a,b)=>Convert.ToString(a+b);

            Console.WriteLine(mydel(100,200));

            Console.ReadKey();

        }

        public static string MyMethod(int a, int b)

        {

            return Convert.ToString(a + b);

        }

No wonder the output would be 300.