EmployeeApp

A classic n-tier .NET solution for managing companies and their employees, demonstrating how multiple client applications (WPF desktop, ASP.NET MVC web) can share the same business logic and data access layers through a REST Web API.

Solution Structure

Project	Type	Role
`DTO`	Class library	Shared data transfer objects (`Company`, `Employee`)
`EmployeeDataAccess`	Class library	Entity Framework context, entities, repositories, and entity↔DTO mappers
`BusinessLogic`	Class library	Business rules (`CompanyBLL`, `EmployeeBLL`)
`WebAPI`	ASP.NET Web API	REST endpoints (`CompanyApiController`, `EmployeeApiController`)
`WebGUI`	ASP.NET MVC	Web frontend consuming the API (`Company`/`Employee`/`Home` controllers)
`EmployeeWPF`	WPF	Desktop client
`TestApp` / `testAPI`	WPF / Web API	Test harness clients

Architecture

EmployeeWPF (desktop)      WebGUI (ASP.NET MVC)
        \                     /
         \                   /
          WebAPI  (ASP.NET Web API, REST)
                |
          BusinessLogic (BLL)
                |
          EmployeeDataAccess (EF, repository + mapper pattern)
                |
          SQL Server (Entity Framework, seeded via EmployeeInitializer)

Key patterns: repository pattern, DTO mapping between persistence entities and transport objects, and strict layering - clients never touch the database directly.

Tech Stack

C# / .NET Framework 4.8
ASP.NET Web API 2 & ASP.NET MVC 5
Entity Framework (code-first with database initializer/seeding)
WPF
IIS Express / Visual Studio or JetBrains Rider

Running

Open EmployeeApp.sln in Visual Studio or Rider.
Set WebAPI as the startup project and run it (IIS Express). EF creates and seeds the database on first run.
Start WebGUI and/or EmployeeWPF to use the web or desktop client against the API.