WEB API Programming in ASP.NET Core 3.1

Explore the .NET core overview, a cross-platform, cloud-first framework using C# to build Windows, Linux, and macOS apps with APIs, libraries, Docker and CI/CD pipelines.

Discover the unified story of ASP.NET Core 3.1, using a common object model for forms, MVC views, and API services, with dependency injection.

Explore the asp.net core 3.1 ecosystem, including entity framework for data access with database first and code first approaches, and a unified domain and shared library strategy.

Create a new ASP.NET Core 3.1 API project using the API template with MVC, set authentication to none, deploy to Linux or Windows, and generate a self-signed certificate.

Explore the startup class in ASP.NET Core 3.1, focusing on dependency injection and configuration. Learn how ConfigureServices registers controllers, context, repositories, authentication, authorization, and policy for security.

Create category and product model classes, establish a one-to-many relation with foreign keys and navigation properties, and apply data annotations for validation in an ASP.NET Core 3.1 Web API.

Configure the DbContext and install Entity Framework Core NuGet packages to map entity classes to database tables, using migrations and a localdb connection string with integrated security.

Register a DbContext in startup configuration, configure dependency injection with a SQL Server connection string, map DbSet<Category> and DbSet<Product>, and apply OnModelCreating for the category‑product relationship and migrations.

Define a one-to-many relationship between category and product using entity framework core, with navigation properties and a foreign key, and apply migrations via on model creating method.

Execute code-first migrations in Entity Framework Core to generate the first migration, define up and down methods, create categories and products tables, and update the database via the command line.

learn to build a SQL database for a web api using Entity Framework Core code-first migrations, defining product and category entities, establishing relationships, and validating connections.

Configure dependency injection for the generic asynchronous repository interface in the services folder to support create, read, update, and delete operations on entity types via a primary key.

Create a category service by implementing the category interface and injecting the db context, delivering async create, read, update, and delete operations for categories.

Explore how dependency injection in ASP.NET Core uses a container to manage transient, scoped, and singleton lifetimes, and how to register services in startup, including db context lifetimes.

Explore how to register category and product services with dependency injection in startup configuration, choosing appropriate lifetimes (singleton, scoped) and ensuring the DbContext is scoped to API requests.

Create an api controller class in ASP.NET Core 3.1, select the right template, and implement action results with ControllerBase and ApiController attributes.

Explore api controller design in ASP.NET Core 3.1 with repository and service layers, constructor injection, model state validation, and http method mapping for get, post, put, and delete.

Debug web api methods by applying attributes to fix get and post endpoints, explore constructor injection and template inputs, and validate service configuration in startup and api context.

Test web api methods in postman by sending json to the category api, validate the model, and trace the create flow through the category service and response formatting.

Override the default json serialization in ASP.NET Core 3.1 by configuring json serializer options and a property naming policy, using System.Text.Json and Postman for testing.

Learn how to self-host a web API in ASP.NET Core 3.1 by running the app from the console, observing port bindings, and comparing self-hosting with IIS Express.

Learn how the ApiController attribute in ASP.NET Core 3.1 enables posting requests by mapping the request body to a model object via the API controller, as shown using Postman.

Explore model binding for post methods in ASP.NET Core 3.1 API controllers, showing how FromBody, FromQuery, and FromForm map data into a bound model automatically.

Learn how the FromBody binder binds data posted to an ASP.NET Core API controller, using a post request, action method, and Postman to validate model binding from the request body.

Demonstrates using FromRoute and FromForm binders to map route and form data to a C# model in ASP.NET Core 3.1, with a Postman workflow.

Discover how Swagger documents and tests REST APIs in ASP.NET Core, exposing endpoints to third-party clients. Swagger generates a browser UI listing methods with inputs and outputs for testing.

Learn to implement data annotations for built-in validators in ASP.NET Core 3.1, test them with Postman, and extend with custom validations to ensure category data meets validation rules.

Implement a custom validator in ASP.NET Core 3.1 by deriving from ValidationAttribute and overriding IsValid to ensure a positive base price, with server-side validation and custom errors.

Explore how ASP.NET Core processes requests via a unified hosting and middleware pipeline. Configure services, routing, and controllers while middleware handles authentication, authorization, model binding, and exceptions.

Discover how middleware in ASP.NET Core manages the request and response through a pipeline, delegating to next components, and injecting custom features like authentication, routing, and exception handling.

Learn how to create and apply a custom exception middleware in ASP.NET Core 3.1 by adding an extension method to the application builder and wiring it into the pipeline.