Shrinath: Action, Delegate, Lambda expression and Callbacks in C#

	using System.Collections;
	using System.Collections.Generic;
	using UnityEngine;
	using System;

	public class ActionDemo : MonoBehaviour {

	void Start(){
	Action<string> SampleAction; //action dont need an explicit delegate to be declared (Action is special kind of delegate which takes parameters but returns nothing)

	SampleAction = PrintMsg;
	SampleAction += delegate(string s) {Debug.Log("from anonymous method : "+s);} ; //using anonymous method
	SampleAction += s => Debug.Log("using lambda expression : "+s); //using lambda expression
	SampleAction ("Hello shrinath");
	}

	void PrintMsg(string msg1){
	Debug.Log ("msg : " + msg1);
	}
	}

view raw ActionDemo.cs hosted with ❤ by GitHub

	using System.Collections;
	using System.Collections.Generic;
	using UnityEngine;
	using System;

	public class CallbackUsingActionAndLambdaDemo : MonoBehaviour {

	void Start(){
	DoWork ((String result) => Debug.Log (result)); //passing the executable code to DoWork() as a callback (after doing work in DoWork(), the code which has been sent will be executed)
	}

	public void DoWork(Action<string> callback){
	bool isWorkDone;

	//do work here
	isWorkDone = true;

	if (isWorkDone)
	callback ("yes work is done successfully");
	else
	callback ("sorry work is not done");

	}
	}

	using System.Collections;
	using System.Collections.Generic;
	using UnityEngine;

	public class CallbackUsingDelegateDemo : MonoBehaviour {

	public delegate void WorkCompletedCallBack(string result);

	public void DoWork(WorkCompletedCallBack callback){
	bool isWorkDone;

	//do work here

	isWorkDone = true;

	if (isWorkDone)
	callback ("yes work done successfully...");
	else
	callback ("sorry work not done...");
	}

	void Start(){
	WorkCompletedCallBack workResultCallback = ShowWorkResult;
	DoWork (workResultCallback);
	}

	//this is the callback which is called when the work is done in DoWork()
	public void ShowWorkResult(string result){
	Debug.Log (result);
	}
	}

	using System.Collections;
	using System.Collections.Generic;
	using UnityEngine;

	public class DelegateDemo : MonoBehaviour {
	public delegate void Del(string msg);

	void Start(){
	Del SampleDel;

	SampleDel = PrintMsg;
	SampleDel += Debug.Log; //using plus sign we can subscribe multiple methods to trigger events.
	SampleDel("Hello Shrinath..."); //when this is called, all the methods subscribed to this delegate gets called
	}

	void PrintMsg(string msg1){
	Debug.Log ("msg : " + msg1);
	}
	}

view raw DelegateDemo.cs hosted with ❤ by GitHub

Shrinath