Building class libraries
Class library assemblies group types together into easily deployable units (DLL files). So far, you have only created console applications to contain all your code. To make the code that you write reusable across multiple projects, you should put it in class library assemblies, just like Microsoft does.
Put types that you might reuse in a class library.
Creating a class library to share code
Start Microsoft Visual Studio 2015. In Visual Studio, press Ctrl + Shift + N or go to File | New | Project….
In the New Project dialog, in the Installed Templates list, select Visual C#. In the center list, select Class Library, type Name as Ch06_PacktLibrary, change Location to
C:\Code, type Solution name as Chapter06, and then click ...