As this is the interface, I will name this as IEmployeeDataServices.
Next, add IEmployeeDataServices interface class. Right-click the Employees.IDataServices Project folder and select Add > New Item.
In the Add New Item dialog, select the Class template. Name the class IEmployeeDataServices and click OK.
A dataservices is an object that encapsulates the data layer, and contains logic for retrieving data and mapping it to an entity model. Even though the example app doesn’t use a database, it’s useful to see how you can inject a repository into your controllers.
Replace the generated code with the below:
Build this project by clicking Ctrl+Shift+B in order to create dll as this project will be used as a reference for the other projects and make sure there is no build error.
Create a DataServices Project,
In Solution Explorer, right click the src folder and select Add > New Project.
In the Add Project dialog, select the Class Library template. Name the project Employees.DataSerivces and click OK.