ASP.NET Core Deep-Dive In .NET 11

Explore the HTTP protocol by examining the HTTP request syntax: the method, URL, and version on the request line, headers, the host header, and the optional body.

Explore how the HTTP request is translated into an HTTP context, then access the method, path, headers, and body, and output them with the response in ASP.NET Core.

Learn how the http get method retrieves information from the server, using method and url to route requests and display an in-memory employee list.

Learn how the http post method creates new server resources by sending json in the request body, deserializing it to an employee, and adding it to an in-memory data store.

Learn how HTTP put updates existing resources by routing by method and location, reading the JSON body, deserializing to an employee object, and updating the in-memory store.

Learn how the query string passes key value pairs in a URL like id=1 and name=frank, and how kestrel exposes them via the http context request.query dictionary.

Learn how the HTTP delete method removes a specific resource using a query string id, implement a delete endpoint, parse the id, and handle success or not found responses.

Learn how HTTP request headers carry authentication and authorization data, why they beat long query strings, and implement a simple authorization check using the Authorization header to permit deletes.

Refactor the routing code to route by location first, then by http verb, improving endpoint organization for employees and other resources, with get, post, put, and delete tests.

Explore http response syntax, including the response line with version, status code, and description, along with headers and body, to understand how the browser renders content.

Explore the HTTP response in HttpContext, set status codes (200, 201, 204), manage headers and the body as a stream, and emit HTML with the correct content type.

Learn HTTP response status codes in ASP.NET Core, from informational 100 to ok 200 and created 201. Explore redirects 301/302, client errors 400/401/404, and server errors 500 with practical examples.

Create an endpoint to retrieve a particular employee by query string from the in-memory data store and display the information as HTML.

Implement get by id logic for the employee endpoint in ASP.NET Core, reading id from the query string, querying the repository, and returning HTML content or 404 when not found.

Examine the middleware pipeline theory in ASP.NET Core, showing how an HTTP context flows through sequential middleware components, decoupling routing, authentication, authorization, and model binding for scalable, maintainable web apps.

Explore building middleware in ASP.NET Core using app.Use to create regular and terminal middleware, wire a multi-layer pipeline, pass the http context to the next delegate, and observe request flow.

Explore how to use app.run to create terminal middleware in ASP.NET Core, compare it with app.use, and learn how terminal middleware short-circuits the pipeline without a next delegate.

Use app.Map to branch an ASP.NET Core middleware pipeline and route /employees to a separate sub-pipeline. This branch runs its own middleware components and does not rejoin the main pipeline.

Learn to branch the ASP.NET Core pipeline with MapWhen by using a HttpContext-based condition to route to a separate branch when a query string id is present.

Demonstrate using use when to create a rejoining branch in the middleware pipeline, showing how the branch reattaches to the main flow after execution.

Modify headers and status codes before calling response, as once the response starts streaming, post-send changes fail; ensure content-length consistency and order with middleware to avoid header and body mismatches.

Discover built-in middleware components that form the core of the ASP.NET Core pipeline, including routing, authentication, authorization, model binding, and validation, and learn their typical order.

Create a class that implements the IMiddleware interface, register it as a transient service, and use app.UseMiddleware<MyCustomMiddleware>() to add it to the request pipeline.

Develop a custom exception handling middleware in ASP.NET Core as a separate class, and explore its placement in the middleware order to render a simple HTML error response.

Create a custom exception handling middleware at the start of the pipeline to catch all exceptions, log them, and return an html error response.

Understand how routing maps requests to endpoints that handle and respond. Identify endpoints by http method and url, and explore minimal API, IVC, browser pages, and middleware in ASP.NET Core.

Configure routing middleware before endpoint middleware, enabling routing to match requests to endpoint identities and populate the HTTP context with the selected endpoint for downstream authentication and authorization.

Explain how the 404 not found middleware handles requests when routing cannot find a matching endpoint, generating a 404 page in the default pipeline.

Explore required route parameters in ASP.NET Core by defining root templates with literal segments and curly brace variables. See how route matching stores parameter values for SEO-friendly URLs like delete.

Define route parameters with default values using the {param=default} syntax in ASP.NET Core route templates. Omitting trailing segments maps to their defaults, enabling flexible routes with category and size examples.

Learn how optional route parameters work in ASP.NET Core, using a trailing question mark in curly brace syntax, and how omitting end path segments affects route values.

Discover route parameter constraints in ASP.NET Core, distinguishing endpoints by type with Visual Studio examples, including integer and string constraints and how mismatches yield a 404.

apply a custom parameter constraint in ASP.NET Core to restrict a route parameter to manager or developer, register and use it in a route such as employees/positions/{position}, with case-insensitive checks.

Implement CRUD operations for employees using endpoint middleware and routing, backed by an in-memory datastore, with endpoints to create, read all, read by id, update, and delete.

Implement CRUD operations with proper routing in an ASP.NET Core app, using models and an employees repository, exposing endpoints for get all, get by id, post, put, and delete.

Discover how ASP.NET Core model binding extracts data from route values, query strings, headers, and body to populate endpoint handler parameters, letting you focus on business logic.

Apply explicit and implicit from-root binding in minimal APIs to map route parameters to root values, return JSON from an in-memory data store, and handle optional parameters and basic errors.

Learn to bind query string values to endpoint handler parameters, using implicit binding when names match and explicit binding when they differ, with route values taking priority.

Bind endpoint parameters from http headers using explicit binding in ASP.NET Core; learn how header names must match parameter names or be configured to avoid bad requests.

discover how as parameters group multiple HTTP request inputs—route id, query name, and header position—into a single class or struct, simplifying model binding in ASP.NET Core.

Bind an int array from query strings or headers to an ASP.NET Core endpoint parameter, then fetch multiple employees by filtering with ids and return as a JSON array.

Bind a complex type from the HTTP body using model binding, and demonstrate json deserialization while highlighting minimal API limits: only JSON, one complex type, and post/put/patch usage.

Master custom binding in ASP.NET Core by implementing a static bind async method that binds a complex type from query string or header using the HTTP context.

Master binding source priorities in asp.net core: explicit binding takes precedence, then complex types with bind async, then route parameters, then primitive query types, then headers, and finally the body.

Explore model validation in ASP.NET Core by leveraging model binding, data annotations, and minimal APIs to enforce required fields and ranges on endpoint inputs.

Apply custom model validation with a validation attribute to enforce multi-property rules, such as a manager's salary greater or equal to $100,000, using data annotations and minimal APIs.

Bind and validate registration information—email, password, and confirm password—enforcing required fields, email format, six-character minimum, matching passwords, using model binding and validation with endpoint variants (query strings and http body).

Demonstrates binding and validating registration data in ASP.NET Core with data annotations, using get query string and post body; explains why post body is more secure.

Master minimal API return types in ASP.NET Core by using IResult, Results, and typed results to produce JSON or text responses with correct HTTP status codes.

Learn how to mix and match results and type results in a post endpoint, returning 201 created with a location header while managing id generation in an employee repository.

Explains the problem details standard (RFC 7807) for HTTP errors and demonstrates implementing it in ASP.NET Core using validation problem and dictionary-based messages for consistent, public API responses.

Standardize api results by configuring exception handling and status code middleware to return consistent, RFC 7807 compliant json problem details for errors and missing routes.

Learn to customize responses by implementing the IResult interface and building an HTML result class that returns HTML from an API endpoint, with proper text/html content type.

Implement CRUD for employees using the minimal api extensions nuget package by adding get by id, put, and delete endpoints with type results and results.validation_problem, enabling parameter validation.

Demonstrate implementing CRUD for employees in a .NET 9 ASP.NET core app, including get by id, update, and delete, with proper validation and 400/404 status handling.

Organize minimal api endpoints for employees with extension methods and dependency injection in a dedicated endpoints folder, moving endpoint logic from program.cs into a static class and a map method.

Explore how tightly coupling the web API to the employees repository creates maintenance and collaboration challenges, and learn how dependency injection and inversion of control decouple these components.

Learn how the dependency inversion principle uses a shared interface to invert dependencies between the API definition and the repository, so both depend on abstraction rather than the concrete implementation.

Learn how inversion of control enables loosely coupled components by injecting concrete implementations via an interface, with the ASP.NET Core dependency injection container handling creation and disposal.

Explore lifetime management in ASP.NET Core dependency injection, covering singleton, scoped, and transient lifetimes. See how the framework instantiates and disposes objects across a middleware pipeline with an in-memory repository.

Explore why MVC controllers organize related endpoints into a class, how to create a department controller, and when to choose MVC over minimal API for structured routing and HTML UI.

Explore how attribute routing maps HTTP requests to controller actions in ASP.NET Core, using HTTP method and route attributes, conventions, and top-level route registrations.

Demonstrate conventional routing in asp.net core using a master route template with map controller route, default controller, action, and optional id, alongside attribute routing and HTTP methods.

Learn how controllers bind to form fields and form data, contrast with minimal APIs, and see how simple forms bind via form url encoded data to action methods.

Explore complex types in ASP.NET Core, compare model binding in minimal APIs and controllers, and learn why controllers require binding from body while default sources can be form or query.

Explore binding source priorities in ASP.NET Core controllers, from explicit binding and binding async to form fields outranking route parameters and query strings, and learn array and header binding.

Explore how model binding in controllers creates a complex object with default values when the HTTP request lacks data, then compare to minimal API’s 400 response and attribute binding.

Learn how input formatters bind data from the http body using json or xml, configure them in Program.cs, and enable json and xml support for model binding.

Learn how model state stores validation errors in mvc controllers as a dictionary. Inspect entries, add custom errors with add model error, and compare with minimal api behavior.

Explore the key differences of ASP.NET Core MVC controllers, focusing on view results for HTML UI, and other results such as content, JSON, file, and redirect results.

Explore returning content results in ASP.NET Core, using ContentResult with content, content type, and status code in MVC controllers, and apply helper methods for minimal APIs.

Learn how to return json only with json result and the json helper. See how the accept header and output formatters influence xml versus json outputs.

Explore how to serve files in ASP.NET Core using virtual file, physical file, and file content results, including mime types, root folder access, and browser behavior.

Explore redirect results in ASP.NET Core: redirect to action, local redirect, and external URL redirects using action methods, controllers, and route values, with 302 and 301 status guidance.

Implement a CRUD UI for departments in ASP.NET Core using MVC controllers and content result HTML, featuring list, details, create, update, and delete operations.

Learn to implement a CRUD UI for departments using ASP.NET Core MVC. Use controllers, routing, and a mock repository to handle create, details, edit, and delete with form posting.