How do I use a C# Class Library in a project?


C# Problem Overview

I've created a new Class Library in C# and want to use it in one of my other C# projects - how do I do this?

C# Solutions

Solution 1 - C#

Add a reference to it in your project and a using clause at the top of the CS file where you want to use it.

Adding a reference:

  1. In Visual Studio, click Project, and then Add Reference.
  2. Click the Browse tab and locate the DLL you want to add a reference to.
    NOTE: Apparently using Browse is bad form if the DLL you want to use is in the same project. Instead, right-click the Project and then click Add Reference, then select the appropriate class from the Project tab:
    enter image description here
  3. Click OK.

Adding a using clause:

Add "using [namespace];" to the CS file where you want to reference your library. So, if the library you want to reference has a namespace called MyLibrary, add the following to the CS file:

using MyLibrary;

Solution 2 - C#

In the Solution Explorer window, right click the project you want to use your class library from and click the 'Add Reference' menu item. Then if the class library is in the same solution file, go to the projects tab and select it; if it's not in the same tab, you can go to the Browse tab and find it that way.

Then you can use anything in that assembly.

Solution 3 - C#

I'm not certain why everyone is claiming that you need a using statement at the top of your file, as this is entirely unnecessary.

Right-click on the "References" folder in your project and select "Add Reference". If your new class library is a project in the same solution, select the "Project" tab and pick the project. If the new library is NOT in the same solution, click the "Browse" tab and find the .dll for your new project.

Solution 4 - C#">Here</a> is a good article on creating and adding a class library. Even shows how to create Methods through the method wizard and how to use it in the application

Solution 5 - C#

Right Click on Project--> Add--> New Project-->click on Class Library.

Now your class library is created as class1.cs

Right Click on References(of your program/console app)

-->Add Reference-->classLibrary1(whatever you named) Now mention "using ClassLibrary1" in your program/console app

Now u can easily call the method/property in your console app

Solution 6 - C#

  1. Add a reference to your library
  2. Import the namespace
  3. Consume the types in your library

Solution 7 - C#

Add it as a reference.

References > Add Reference > Browse for your DLL.

You will then need to add a using statement to the top of your code.

Solution 8 - C#

You need to add a reference to your class library from your project. Right click on the references folder and click add reference. You can either browse for the DLL or, if your class libaray is a project in your solution you can add a project reference.

Solution 9 - C#

There are necessary steps that are missing in the above answers to work for all levels of devs:

  1. compile your class library project
  2. the dll file will be available in the bin folder
  3. in another project, right click ProjectName and select "Add" => "Existing Item"
  4. Browser to the bin folder of the class library project and select the dll file (3 & 4 steps are important if you plan to ship your app to other machines)
  5. as others mentioned, add reference to the dll file you "just" added to your project
  6. as @Adam mentioned, just call the library name from anywhere in your program, you do not need a using statement


All content for this solution is sourced from the original question on Stackoverflow.

The content on this page is licensed under the Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license.

Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionNosramaView Question on Stackoverflow
Solution 1 - C#Michael ToddView Answer on Stackoverflow
Solution 2 - C#Max SchmelingView Answer on Stackoverflow
Solution 3 - C#Adam RobinsonView Answer on Stackoverflow
Solution 4 - C#SwDevMan81View Answer on Stackoverflow
Solution 5 - C#sohan yadavView Answer on Stackoverflow
Solution 6 - C#Kent BoogaartView Answer on Stackoverflow
Solution 7 - C#Daniel MayView Answer on Stackoverflow
Solution 8 - C#CharlieView Answer on Stackoverflow
Solution 9 - C#usefulBeeView Answer on Stackoverflow