Creating DLL (Class Library) in .NET Framework

This article shows how to create a Class Library project and include it in a web application project. ASP.NET is part of the Microsoft .NET Framework. To build ASP.NET pages, you need to take advantage of the features of the .NET Framework. A Class Library is one of them. A Class Library contains one or more classes that can be called on to perform specific actions. Creating a Class Library makes a DLL that can be used for reusability.

Creating Class Library

Now open the Visual Studio and select "File" -> "New" -> "Project..." -> "Class Library". The following code will be generated:

Class Library1.jpg

Now click on the "Ok" button. The Solution Explorer contains C# classes (class.cs) in your project. Now replace the default code (shown above) with the following code:

  1. using System;  
  2. using System.Collections.Generic;  
  3. using System.Linq;  
  4. using System.Text;  
  5. namespace ClassliberaryDemo  
  6. {  
  7.     public class PersonalDetail  
  8.     {  
  9.         private string _firstname;  
  10.         private string _lastname;  
  11.         private string _Email;  
  12.         private long  _PhoneNumber;  
  13.         public string FirstName  
  14.         {  
  15.             get { return _firstname; }  
  16.             set { _firstname = value; }  
  17.         }  
  18.         public string LastName  
  19.         {  
  20.             get { return _lastname; }  
  21.             set { _lastname = value; }  
  22.         }  
  23.         public string Email  
  24.         {  
  25.             get { return _Email; }  
  26.             set { _Email = value; }  
  27.         }  
  28.         public long  PhoneNumber  
  29.         {  
  30.             get { return _PhoneNumber; }  
  31.             set { _PhoneNumber = value; }  
  32.         }  
  33.     }  
  34. } 

Now build this project. After building this project, you will see ClassLibrary1.dll in your project's bin/debug directory.

Class-Library2.jpg

Now open the Visual Studio again and select "File" -> "New" -> "Project..." -> "ASP.NET web application"

Class-Library3.jpg

Now add the reference of the preceding created DLL. To add a reference right-click on the project then seelct "Add Reference".

Class-Library4.jpg

Now browse to the ClassLibrary1.dll file and add it to the application.

Class-Library5.jpg

Use the following procedure to call the properties of your component.

Using namespace

Add a using statement (as in the following) for ClassliberaryDemo to the beginning of your project.

  1. using ClassliberaryDemo;

Create an Object of the "PersonalDetail" class, as in the following:

  1. PersonalDetail PD = new PersonalDetail();

Now Calling Properties

Class-Library6.jpg