24 January 2017
As you start your journey with .NET Core, one of the first things you’ll need to understand is how to structure your projects and solutions. Proper project organization is essential for scalability, maintainability, and collaboration, especially as your application grows in complexity.
In this post, we’ll take a closer look at the key aspects of .NET Core projects and how to set up a solution structure that best suits your needs. We’ll also discuss the different types of projects you can create with .NET Core and how they fit into the larger picture of application development.
1. What Is a .NET Core Project?
In .NET Core, a project is a unit of code that defines the logic and resources for a specific task or function within your application. A project typically contains source code files, libraries, and configuration files needed to run and build the application.
Projects in .NET Core are often organized into a single solution. A solution is a container that can hold one or more projects. This structure makes it easy to manage complex applications with multiple components that may serve different purposes (e.g., a web API, a console app, or a shared class library).
The idea is that a solution represents the overall application, while a project is a building block of that solution.
2. Understanding the .NET Core Solution Structure
A .NET Core solution typically consists of the following components:
- Solution file (.sln): This is the main file that contains references to the projects within the solution. It keeps track of all the individual projects that make up your application.
- Project files (.csproj): These files define the specific configurations for each project, such as the project type, dependencies, and target framework.
As a rule of thumb, a solution file can contain multiple projects. For example, you may have a solution that contains:
- A Web API project
- A Console Application project
- A Class Library project
- A Unit Test project
This modular approach to structuring projects helps ensure that different parts of your application can evolve independently while still being part of the same overall solution.
3. Different Project Types in .NET Core
When working with .NET Core, you will encounter several different types of projects, each designed for specific use cases. Below are some of the most common project types in .NET Core:
a. Console Application
A Console Application is the most basic type of application you can create in .NET Core. It runs in the command-line interface (CLI) and is typically used for small utilities or background tasks.
- Use Case: Ideal for simple tasks, tools, or small projects that do not require a user interface (UI).
- Example: A file-processing tool, a background service, or a batch script.
To create a console app in .NET Core, you can use the following command:
dotnet new console -n MyConsoleApp
b. Web API
A Web API is a project designed to expose data or services over HTTP. It’s one of the most common types of applications used in modern software development, especially for building RESTful services.
- Use Case: Ideal for creating web services or backend APIs that can be consumed by mobile apps, web apps, or other services.
- Example: A product catalog API, a user authentication service, or a data retrieval API.
To create a Web API in .NET Core, use the following command:
dotnet new webapi -n MyWebApi
c. Class Library
A Class Library project contains reusable code that can be referenced by other projects. Class libraries are typically used to define the core logic of your application, which can then be shared across multiple projects within the same solution.
- Use Case: Ideal for code that needs to be shared across different projects (e.g., business logic, data models, utility functions).
- Example: A library for handling authentication, data validation, or logging.
To create a class library, use this command:
dotnet new classlib -n MyClassLibrary
d. Unit Test Project
A Unit Test Project is used for writing tests for your application. .NET Core supports xUnit, NUnit, and MSTest as the default testing frameworks. Writing unit tests ensures that the functionality of your code works as expected and helps maintain code quality over time.
- Use Case: Ideal for testing the individual components of your application to ensure they perform as intended.
- Example: Writing tests for your Web API controllers or business logic methods.
To create a unit test project, use this command:
dotnet new xunit -n MyUnitTests
e. Blazor WebAssembly
With Blazor, you can build interactive web applications using C# instead of JavaScript. Blazor WebAssembly runs client-side directly in the browser using WebAssembly, which allows you to write rich, interactive web apps entirely in C#.
- Use Case: Ideal for building Single Page Applications (SPAs) without using JavaScript.
- Example: A task manager app or a personal blog.
To create a Blazor WebAssembly app, use this command:
dotnet new blazorwasm -n MyBlazorApp
4. Organizing Projects in a Solution
Once you understand the different project types, it’s time to organize them within a solution. Here’s an example structure for a web-based application:
- MyApp.sln (solution file)
- MyApp.Web (Web API project)
- MyApp.Core (Class Library project)
- MyApp.Tests (Unit Test project)
This organization keeps related projects together in a single solution, making it easier to manage and scale your application. You can use the dotnet sln command to add projects to your solution:
dotnet sln MyApp.sln add MyApp.Web/MyApp.Web.csproj
dotnet sln MyApp.sln add MyApp.Core/MyApp.Core.csproj
dotnet sln MyApp.sln add MyApp.Tests/MyApp.Tests.csproj
5. Building and Running Projects in a Solution
After you’ve set up your projects, you can build and run them together. You can build the entire solution with the following command:
dotnet build MyApp.sln
To run a specific project, navigate to the project directory and use the dotnet run command. For example, to run the Web API project:
cd MyApp.Web
dotnet run
6. Conclusion
Understanding how to structure .NET Core projects and solutions is key to building maintainable, scalable applications. By organizing your projects effectively and using the right project types, you can ensure that your codebase remains clean and manageable as your application grows.
Whether you’re building a simple console app or a complex web API, .NET Core provides the flexibility to choose the best project structure for your needs.
