The goal of this project is to enable .NET programmers to learn the new ASP.NET Core stack from the ground up directly from code. I will not address ASP.NET Core MVC in this project. There is so much power in the underlying ASP.NET Core stack. Don't miss them!

You will need to download the latest release version .NET Core SDK to be able to run these samples.

If you are running these samples on Linux, change the target framework inside the csproj files from

<TargetFramework>net461</TargetFramework>

to

<TargetFramework>netcoreapp1.1</TargetFramework>

Every sample is designed specifically to demonstrate a single idea. We will go wide and deep to the nitty gritty of ASP.NET Core stack. Enjoy the ride!

Some of the samples you see here involve mixed projects (net461) that will run only in Windows. For many .NET developers, full framework is the reality for forseeable future. We are not going to port multi-year production systems to run on Linux. We want to improve the creaky .NET MVC 2.0 that we have lying around and bring it up to speed to aspnetcore MVC.

All these projects require the following dependencies

   "Microsoft.AspNetCore.Hosting" : "1.1.0-*"

If a sample require additional dependencies, I will list them.

I highly recommend using Visual Studio Code to play around with these samples but it is not required. You can use Visual Studio 2017 as well.

To run these samples, simply open your command line console, go to each folder and execute dotnet restore and then continue with dotnet watch run.

• Hello World (21)

  • Hello World with reload

    Setup your most basic web app and enable the change+refresh development experience.

    We are using IApplicationBuilder Run, an extension method for adding terminal middleware.

  • Startup class

    • Hello World with startup basic

      This project contains all the available services available in Startup class constructor, ConfigureServices and Configure methods.

    • Hello World with custom startup class name

      You don't have to call your startup class Startup. Any valid C# class will do.

    • Hello World with responding to multiple urls

      Configure so that your web app responds to multiple urls.

    • Hello World with multiple startups

      This project highlights the fact that you can create multiple Startup classes and choose them at start depending on your needs.

    • Hello World with multiple startups using environment

      This project highlights the fact that you can create multiple startup classes and choose them at start depending on your needs depending on your environment (You do have to name the startup class with Startup).

    • Hello World with multiple Configure methods based on environment

      This project demonstrates the ability to pick Configure method in a single Startup class based on environment.

    • Hello World with multiple ConfigureServices methods based on environment

      This project demonstrates the ability to pick ConfigureServices method in a single Startup class based on environment.

    • Hello World with an implementation of IStartup interface

      We are really getting into the weed of startup right now. This is an example on how to implement IStartup directly.

    • Hello World without a startup class

      Why? just because we can.

    • Hello world with IStartupFilter

      Use IStartupFilter to configure your middleware. This is an advanced topic. This article tries at explaining IStartupFilter. I will add more samples so IStartupFilter can be clearer.

  • Show errors during startup

    Show a detailed report on exceptions that happen during the startup phase of your web app. It is very useful during development.

  • Show Connection info

    Enumerate the connection information of a HTTP request.

  • Environmental settings

    Set your application environment to Development or Production or other mode directly from code.

  • Console logging

    Setup a basic logging in your app and show it to console.

    We add the following dependencies "Microsoft.Extensions.Logging": "1.1.0" and "Microsoft.Extensions.Logging.Console": "1.1.0"

    We are using IApplicationBuilder Run, an extension method for adding terminal middleware.

  • Console logging - without framework log messages

    Filter out frameworking logging from your log output. Without filtering, logging can get very annoying becuase the framework produces a lot of messages.

  • Hello World with middlewares

    ASPNetCore is built on top of pipelines of functions called middleware.

    We are using IApplicationBuilder Use, an extension method for adding middleware and IApplicationBuilder Run.

  • IApplicationLifetime

    Respond to application startup and shutdown.

    We are using IApplicationLifetime that trigger events during application startup and shutdown.

  • IHostingEnvironment

    IHostingEnvironment is available at Startup constuctor and Startup.Configure. This sample shows all the properties available in this interface.

  • Application Environment

    Requires Microsoft.Extensions.PlatformAbstractions" : "1.1.0-* dependency. This sample shows how to obtain application environment information (target framework, etc).

  • Adding HTTP Response Header

    Demonstrate on how to add a response header and where is allowed place to do it.

• Request(7)

  This section shows all the different ways you capture input and examine request to your web application.

  • HTTP Verb (1)

    • Get request verb

      Detect the verb/method of the current request.

  • Headers (2)

    • Access Request Headers

      Enumerate all the available headers in a request.

    • Type Safe Access to Request Headers

      Instead of using string to access HTTP headers, use type safe object properties to access common HTTP headers.

  • Form (2)

    We take dependency on "Microsoft.AspNetCore.Routing" : "1.1.0-*" to enable routing facilities to make the form handling easier.

    • Form Values

      Handles the values submitted via a form.

    • Form Upload File

      Upload a single file and save it to the current directory (check out the usage of .UseContentRoot(Directory.GetCurrentDirectory()))

  • Cookies (2)

    • Cookies

      Read and write cookies.

    • Removing cookies

      Simply demonstrates on how to remove cookies.

• Routing (9)

  We take dependency on "Microsoft.AspNetCore.Routing" : "1.1.0-*" to enable routing facilities in your aspnetcore apps. There are several samples to illuminate this powerful library.

  • Router

    A single route handler that handles every path request.

  • Router 2

    Two route handler, one for home page (/) and the other takes the rest of the request using asterisk (*) in the url template.

  • Router 3

    We are exploring default handler - this is the entry point to create your own framework.

  • Router 4

    We are mixing optional route parameter, route parameter with default value and default handler.

  • [Router 5]

    This is still broken. I am trying to figure out how to do nested routing. Wish me luck!

  • Router 6

    We are building a template route segment by segment and parts by parts, oldskool. We are using TemplateMatcher, TemplateSegment and TemplatePart.

    Hold your mask, we are going deep.

  • Router 7

    We are creating a routing template with two segments, one with Literal part and the other Parameter part, e.g, "/page/{*title}"

  • Router 8

    We are creating a routing template with one segment consisted of two parts, one Literal and one Parameter, e.g. "/page{*title}". Note the difference between this example and Router 7.

  • Router 9

    I am still trying to determine whether TemplateMatcher uses the InlineConstraint information.

    Update: No, TemplateMatcher does not run constraints. #362

  • Router 10

    We have been building a RouteTemplate manually using TemplateSegment and TemplatePart. In this example we are using TemplateParser to build the RouteTemplate using string.

• Middleware (8)

  We will explore all aspect of middleware building in this section. There is no extra dependency taken other than Kestrel and dotnet watch.

  • Middleware 1

    This example shows how to pass information from one middleware to another using HttpContext.Items.

  • Middleware 3

    This is the simplest middleware class you can create.

  • Middleware 4

    Use app.Map (MapMiddleware) to configure your middleware pipeline to respond only on specific url path.

  • Middleware 5

    Nested app.Map (show Request.Path and Request.PathBase).

  • Middleware 6

    Use app.MapWhen(MapWhenMiddleware) and Nested app.Map (show Request.Path and Request.PathBase).

  • Middleware 7

    Use MapMiddleware and MapWhenMiddleware directly without using extensions (show Request.Path and Request.PathBase).

  • Middleware 8

    Demonstrate the various ways you can inject dependency to your middleware class manually.

  • Middleware 9

    Demonstrate how to ASP.NET Core built in DI (Dependency Injection) mechanism to provide dependency for your middleware.

• Features (7)

  Features are collection of objects you can obtain from the framework at runtime that serve different purposes.

  • Server Addresses Feature

    Use this Feature to obtain a list of urls that your app is responding to.

  • Request Feature

    Obtain details of a current request. It has some similarity to HttpContext.Request. They are not equal. HttpContext.Request has more properties.

  • Connection Feature

    Use IHttpConnectionFeature interface to obtain local ip/port and remote ip/port.

  • Custom Feature

    Create your own custom Feature and pass it along from a middleware.

  • Custom Feature - Override

    Shows how you can replace an implementation of a Feature with another within the request pipeline.

  • Request Culture Feature

    Use this feature to detect the culture of a web request through IRequestCultureFeature. It needs the following dependency "Microsoft.AspNetCore.Localization": "1.1.0".

  • Session Feature

    Use session within your middlewares. This sample shows a basic usage of in memory session. It needs the following dependency '"Microsoft.AspNetCore.Session" : "1.1.0-"and"Microsoft.Extensions.Caching.Memory" : "1.1.0-"`.

• Dependency Injection (2)

  ASP.NET Corenetcore lives and die by DI. It relies on Microsoft.Extensions.DependencyInjection library. There is no need to put this dependency in your project.json explicitly because aspnetcore already has this package as its own dependency.

  • Dependency Injection 1 - The basic

    Demonstrate the three lifetime registrations for the out of the box DI functionality: singleton (one and only forever), scoped (one in every request) and transient (new everytime).

  • Dependency Injection 3 - Easy registration

    Register all objects configured by classes that implements a specific interface (IBootstrap in this example). This is useful when you have large amount of classes in your project that needs registration. You can register them near where they are (usually in the same folder) instead of registering them somewhere in a giant registration function.

    Note: example 2 is forthcoming. The inspiration has not arrived yet.

• File Provider (2)

  We will deal with various types of file providers supported by ASP.NET Core

  • Physical File Provider - Content and Web roots

    Access the file information on your Web and Content roots.

  • Custom File Provider

    Implement a simple and largely nonsense file provider. It is a good starting point to implement your own proper File Provider.

• In Memory Caching (a.k.a local cache) (4)

  These samples depends on Microsoft.Extensions.Caching.Memory library. Please add this dependency to your project.json.

  • Caching - Absolute/Sliding expiration

    This is the most basic caching you can use either by setting absolute or sliding expiration for your cache. Absolute expiration will remove your cache at a certain point in the future. Sliding expiration will remove your cache after period of inactivity.

  • Caching 2 - File dependency

    Add file dependency to your caching so when the file changes, your cache expires.

    You need to put the cache file in your project.json so it gets copied over, e.g.

    "buildOptions": { "emitEntryPoint": true, "copyToOutput": ["cache-file.txt"] }

    Note: example 1 is forthcoming. The inspiration has not arrived yet.

  • Caching 3 - Cache removal event

    Register callback when a cached value is removed.

  • Caching 4 - CancellationChangeToken dependency

    Bind several cache entries to a single dependency that you can reset manually.

• Configuration (7)

  This section is all about configuration, from memory configuration to INI, JSON and XML.

  • Configuration

    This is the 'hello world' of configuration. Just use a memory based configuration and read/write values to/from it.

  • Configuration - Options

    Use IOptions at the most basic.

  • Configuration - Environment variables

    Load environment variables and display all of them.

  • Configuration - INI file

    Read from INI file. It requires taking a new dependency, "Microsoft.Extensions.Configuration.INI" : "1.1.0".

  • Configuration - INI file - Options

    Read from INI file (with nested keys) and IOptions. It requires taking two new dependencies, "Microsoft.Extensions.Configuration.INI" : "1.1.0" and "Microsoft.Extensions.Options.ConfigurationExtensions" : "1.1.0".

  • Configuration - XML file

    Read from XML file. It requires taking a new dependency, "Microsoft.Extensions.Configuration.Xml" : "1.1.0".

    Note: This Xml Configuration provider does not support repeated element.

    The following configuration settings will break:

    <appSettings>
      <add key="webpages:Version" value="3.0.0.0" />
      <add key="webpages:Enabled" value="false" />
    </appSettings>
    

    On the other hand you can get unlimited nested elements and also attributes.

  • Configuration - XML file - Options

    Read from XML file and use IOptions. It requires taking two new dependencies, "Microsoft.Extensions.Configuration.Xml" : "1.1.0" and "Microsoft.Extensions.Options.ConfigurationExtensions" : "1.1.0".

• Localization and Globalization (4)

  This section is all about languages, culture, etc.

  • Localization

    Shows the most basic use of localization using a resource file. This sample only supports French language (because we are fancy). It needs the following dependency "Microsoft.AspNetCore.Localization": "1.1.0" and "Microsoft.Extensions.Localization": "1.1.0".

  • Localization - 2

    We build upon the previous sample and demonstrate how to switch request culture via query string using the built in QueryStringRequestCultureProvider. This sample supports English and French.

  • Localization - 3

    Demonstrate the difference between Culture and UI Culture.

  • Localization - 4

    Demonstrate how to switch request culture via cookie using the built in CookieRequestCultureProvider. This sample supports English and French.

• URL Redirect/Rewriting (6)

  This section explore the dark arts of URL Rewriting

  • Rewrite

    Shows the most basic of URL rewriting which will redirect (returns HTTP 302) anything to the home page "/". It requires "Microsoft.AspNetCore.Rewrite" : "1.0.0-*" and "Microsoft.AspNetCore.Routing" : "1.1.0-*" dependencies. These two dependencies apply to the rest of the samples in this category.

    If you have used routing yet, I recommend of checking out the routing examples.

  • Rewrite - 2

    Redirect (returns HTTP 302) anything with an extension e.g. about-us.html or welcome.aspx to home page (/). It also shows how to capture the matched regex values.

  • Rewrite - 3

    Rewrite anything with an extension e.g. about-us.html or welcome.aspx to home page (/). It also shows how to capture the matched regex values.

  • Rewrite - 4

    Permanent Redirect (returns HTTP 301) anything with an extension e.g. about-us.html or welcome.aspx to home page (/). It also shows how to capture the matched regex values.

  • Rewrite - 5

    Implement a custom redirect logic based on IRule implementation. Require additional dependency of "Microsoft.AspNetCore.StaticFiles": "1.1.0" to serve images.

    This custom redirection logic allows us to simply specify the image file names without worrying about their exact path e.g.'xx.jpg' and 'yy.png'.

  • Rewrite - 6

    Implement a custom redirect logic using lambda (similar functionality to Rewrite - 5). Require additional dependency of "Microsoft.AspNetCore.StaticFiles": "1.1.0" to serve images.

    This custom redirection logic allows us to simply specify the image file names without worrying about their exact path e.g.'xx.jpg' and 'yy.png'.

• Compression (1)

  Enable the ability to compress ASP.NET Core responses. These samples takes a dependency of Microsoft.AspNetCore.ResponseCompression": "1.0.1.

  • Default Gzip Output Compression

    Compress everything using the default Gzip compression.

    Everything means the following MIME output

    • text/plain
    • text/css
    • application/javascript
    • text/html
    • application/xml
    • text/xml
    • application/json
    • text/json

• Diagnostics(5)

  These samples take a dependency of "Microsoft.AspNetCore.Diagnostics":"1.1.1".

  • Welcome Page

    Simply show a welcome page to indicate that the app is working properly. This sample does not use a startup class simply because it's just a one line code.

  • Developer Exception Page

    Show any unhandled exception in a nicely formatted page with error details. Only use this in development environment!

  • Custom Global Exception Page

    Use IExceptionHandlerFeature feature provided by Microsoft.AspNetCore.Diagnostics.Abstractions to create custom global exception page.

  • Custom Global Exception Page - 2

    Similar to the previous one except that that we use the custom error page defined in separate path.

  • Status Pages

    Use UseStatusCodePagesWithRedirects. Beware: This extension method handles your 5xx return status code by redirecting it to a specific url. It will not handle your application exception in general (for this use UseExceptionHandler - check previous samples).

• Misc (4)

  • Serve static files

    Simply serve static files (html, css, images, etc).

    This additional dependency is required to enable the functionality "Microsoft.AspNetCore.StaticFiles": "1.1.0".

    There are two static files being served in this project, index.html and hello.css. They are stored under wwwroot folder, which is the default folder location for this library.

    To access them you have to refer them directly e.g. localhost:5000/index.html and localhost:5000/hello.css.

  • Markdown server

    Serve markdown file as html file. You will see how you can create useful app using a few basic facilities in aspnetcore.

    We take "CommonMark.Net" : "0.13.4" as dependency.

  • Markdown server - implemented as middleware component

    Serve markdown file as html file. It has the same exact functionality as Markdown server but implemented using middleware component.

    We take "CommonMark.Net" : "0.13.4" as dependency.

    Check out the documentation on how to write your own middleware.

  • Password Hasher server

    Give it a string and it will generate a secure hash for you, e.g. localhost:5000?password=mypassword.

    We add dependency "Microsoft.AspNetCore.Identity": "1.1.0-*" to enable this functionality.

These are other aspnetcore resources with code samples

• aspnetcore documentation

• aspnetcore entropy

  "This repo is a chaotic experimental playground for new features and ideas. Check here for small and simple samples for individual features."

• Put all the code inside Program.cs. It makes it easier for casual users to read the code online and learn something. Sometimes it is too cumbersome to chase down types using browser.
• Keep your sample very simple and specific. Try to minimise the amount of concept that people need to know in order to understand your code.
• There is no sample that is too small. If it shows one single interesting and useful knoweldge, add it in.
• When you are ready, update this document and add the link to the project with a paragraph or two. Do not forget to increment the sample count at the beginning of this document.