Let’s get an understanding of ASP.NET Web API before understanding its real-life application.

ASP.NET Web API

ASP.NET Web API is a lightweight, framework that’s integrated with ASP.NET MVC to create RESTful HTTP services, reaching a broad range of client devices. Utilizing ASP.NET Web API is an adept selection to serve the specific needs of your web application.

Use Cases

• Data Services: It’s perfect for applications that need to expose and manipulate data over the web.
• Mobile Applications: Ideal for back-end support of multi-platform applications, especially REST APIs.
• Single Page Applications (SPAs): Effortlessly integrate with modern JavaScript frameworks for SPAs.
• Real-time Applications: Services like signalR provides real-time communication. Web API can be used to build a real-time API, which apps can consume for real-time data.

Core Advantages

• Ease of Development: Utilizes familiar features from ASP.NET, rendering it simpler to develop.
• Loose Coupling: Supports HTTP services, forming a loosely coupled framework.
• Robust Routing: Employs in-depth routing mechanisms for HTTP requests.
• Content Negotiation: Automatically selects the most fitting response format.
• Model Binding: Directly binds incoming HTTP requests to the specified model or action parameters.
• Action Results: Provides numerous kinds of action results for handling different responses.
• Authentication: Offers multiple levels of data access security.
• Testing: Facilitates direct testing of the API in a dedicated test client.

Code Example: ASP.NET Web API

The standard GET operation for a Web API controller to retrieve a product list from a server:

public IEnumerable<Product> GetProducts()
{
    return productsRepository.All;
}

The code snippet below displays the creation of an ASP.NET Web API controller.

public class ProductsController : ApiController
{
    public IEnumerable<Product> GetProducts()
    {
        return productsRepository.All;
    }
    public Product GetProductById(int id)
    {
        return productsRepository.Find(id);
    }
    public HttpResponseMessage PostProduct(Product product)
    {
        productsRepository.Add(product);
        var response = Request.CreateResponse(HttpStatusCode.Created, product);
        string uri = Url.Link("DefaultApi", new { id = product.Id });
        response.Headers.Location = new Uri(Request.RequestUri, uri);
        return response;
    }
    public void PutProduct(int id, Product product)
    {
        product.Id = id;
        if (!productsRepository.Update(product))
        {
            throw new HttpResponseException(HttpStatusCode.NotFound);
        }
    }
    public void DeleteProduct(int id)
    {
        productsRepository.Remove(id);
    }
}

Key Takeaways

• ASP.NET Web API, an adaptable framework, excels in developing RESTful services for a wide array of consumer devices, applications, and platforms.
• Its robust protocol support and manifold libraries ensure the best possible service for developers who seek to implement modern web service principles.