Creating and Using Dll (Dynamic Link Library) in C#

Previously, we learn about CSS in CSS-3 And CSS-4. now we see how to create DLL's in C#

In this article, I’m explaining how to create and use dl in C#.

1. Create DLL:

Open visual studio >> Select File >> New >> Project >> Windows >> Class Library.

Select your project name and appropriate directory using the browse button and click

OK.

Creating and Using Dll (Dynamic Link Library) in C#

Project and its file:

In this project add two classes by default Class1.cs and AssemblyInfo.cs inside properties folder. We will be concentrating only Class1.cs

Creating and Using Dll (Dynamic Link Library) in C#

Calculator Namespace:

When you open Class1.cs then you see Calculator Namespace. We will be

referencing this Namespace in our clients to use this class method.

using System;
 
namespace Calculator
{
    public class Class1
    {
    }
}

Now add some calculator method in your project.

using System;
 
namespace Calculator
{
    public class Class1
    {
        public static int Add(int num1,int num2)
        {
            return num1 + num2;
        }
        public static int Sub(int num1, int num2)
        {
            return num1 - num2;
        }
        public static int Mul(int num1, int num2)
        {
            return num1 * num2;
        }
        public static int Division(int num1, int num2)
        {
            return num1 / num2;
        }
    }
}

Now Build your project after build succeeded generate Calculator.dll file inside bin >> Debug folder.

Creating and Using Dll (Dynamic Link Library) in C#

Use DLL:

Make a client application for using the DLL file.

Create a console application:

Open visual studio >> Select File >> New >> Project >> Windows >> Console Application.

Select your project name and appropriate directory using the browse button and click OK.

Creating and Using Dll (Dynamic Link Library) in C#

Add reference of the Namespace:

Now add a reference to the library. Project >> Add reference

Creating and Using Dll (Dynamic Link Library) in C#
Now on this page click browse button to browse your library.

Creating and Using Dll (Dynamic Link Library) in C#

Use Calculator Namespace and call method.

using Calculator;
 
namespace UseDll
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Enter Your Operator Choice  Add + Sub - Mul * Division /");
            char choice = Convert.ToChar(Console.Read());
            switch (choice)
            {
                case '+':
                    {
                        int add = Class1.Add(10, 20);
                        Console.WriteLine("Sum of the two number " + add);
                        break;
                    }
                case '-':
                    {
                        int sub = Class1.Sub(50, 20);
                        Console.WriteLine("Substrack of two integer number " + sub);
                        break;
                    }
                case '*':
                    {
                        int mul = Class1.Mul(2, 4);
                        Console.WriteLine(mul);
                        break;
                    }
                case '/':
                    {
                        int div = Class1.Division(10, 2);
                        Console.WriteLine(div);
                        break;
                    }
                default:
                    {
                        Console.WriteLine("Wrong input!!");
                        break;
                    }
            }
        }
    }
}