Action and Anynonymos method using action

1.       An Action is a type of delegate

2.      Encapsulates a method that has a single parameter and does not return a value.

3.       Internally it is deligate and defined as below

Action is a Delegate. It is defined like this:

public delegate void Action();

4.      It may take 0 parameter to 16 parameters.

 

5.       You can use the lambda expression in the action as shown below exapmle

6.       You use Anynonymos method using action as below

Definition	Action<string> sample1 = (string x) => Console.WriteLine("String : 0}", x);
Call	sample1.Invoke("My string ");
Internally Defined	public delegate void Action<in T>(T obj);
Definition	Action<string, string> example2 =          (x, y) => Console.WriteLine("Write {0} and {1}", x, y);
Call	example2.Invoke("string 1", "string 2");
Internally Defined	public delegate void Action<in T1, in T2>(T1 arg1, T2 arg2);

7.    Here is a small example that shows the usefulness of the Action delegate

using System;

using System.Collections.Generic;

class Program

{

    static void Main()

    {

        Action<String> displayString = new Action<String>(Program.DisplyString);

        List<String> collectionOfStrings = new List<String> { "Ajay", "Aarav" };

        collectionOfStrings.ForEach(displayString);

        Console.Read();

    }

    static void DisplyString(String s)

    {

        Console.WriteLine(s);

    }

}

Notice that the foreach method iterates the collection of names and executes the print method against each member of the collection. This a bit of a paradigm shift for us C# developers as we move towards a more functional style of programming. (For more info on the computer science behind it read this