What is Delegates in C# Example | Use of Delegates in C#

What is Delegates in C# Example | Use of Delegates in C# 

 In Simple Language A delegate is an object that can refer to a method. Thus, when you create a delegate, you are creating an object that can hold a reference to a method.

Syntax of Delegate & Methods Declaration

public delegate int Delegatmethod(int a,int b); public class Sampleclass { public int Add(int x, int y) { return x + y; } public int Sub(int x, int y) { return x + y; } }

Example:

public delegate int DelegatSample(int a,int b); public class Sampleclass { public int Add(int x, int y) { return x + y; } public int Sub(int x, int y) { return x - y; } } class Program { static void Main(string[] args) { Sampleclass sc=new Sampleclass(); DelegatSample delgate1 = sc.Add; int i = delgate1(10, 20); Console.WriteLine(i); DelegatSample delgate2 = sc.Sub; int j = delgate2(20, 10); Console.WriteLine(j); } }

Output:

Add Result : 30 Sub Result : 10

Delegates are two types

•       Single Cast Delegates

• Multi Cast Delegates

Syntax of Multicast Delegate & Method Declaration

public delegate void MultiDelegate(int a,int b); public class Sampleclass { public static void Add(int x, int y) { Console.WriteLine("Addition Value: "+(x + y)); } public static void Sub(int x, int y) { Console.WriteLine("Subtraction Value: " + (x - y)); } public static void Mul(int x, int y) { Console.WriteLine("Multiply Value: " + (x * y)); } }

Example

public delegate void MultiDelegate(int a,int b); public class Sampleclass { public static void Add(int x, int y) { Console.WriteLine("Addition Value: "+(x + y)); } public static void Sub(int x, int y) { Console.WriteLine("Subtraction Value: " + (x - y)); } public static void Mul(int x, int y) { Console.WriteLine("Multiply Value: " + (x * y)); } } class Program { static void Main(string[] args) { Sampleclass sc=new Sampleclass(); MultiDelegate del = Sampleclass.Add; del += Sampleclass.Sub; del += Sampleclass.Mul; del(10, 5); Console.ReadLine(); } }

Output:

Addition Value : 15 Subtraction Value : 5 Multiply Value : 50