306 samples for ASP.NET Core 2.1, 2.2, 3.0 and 3.1 fundamentals

There is an active branch that converts all these samples to ASP.NET Core 3.1. This branch was last updated on February 29, 2020.

If you are studying ASP.NET Core, I am lurking on this Gitter Channel.

Hi Nuget visitors, if you have problem finding the sample you are looking for, please use the github search functionality or otherwise file a case. I will be happy to point you to the right direction.

Welcome

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. There is so much power in the underlying ASP.NET Core stack. Don't miss them!

I highly recommend using Visual Studio Code to play around with these samples but it is not required. You can use Visual Studio 2019 as well.

Note: If you encounter problem with downloading packages or Nuget, try the following command nuget.exe locals -clear all.

ASP.NET Core API Browser is also very handy.

Additional Sections

Section No. of Samples .NET Core SDK Version
ASP.NET Core 3.0 57 3.0
Blazor Client Side (Web Assembly) 18 3.1
Blazor Server Side 7 3.0
ASP.NET Core MVC 47 2.1
ASP.NET Core Razor Pages 4 2.2
ASP.NET Core SignalR 1 2.1
Security related samples 1 2.2
Orchard Core Framework 4 3.0
What's new in ASP.NET Core 2.2 14 2.2
What's new in ASP.NET Core 2.1 6 2.1
What's new in ASP.NET Core 2.0 11 Features introduced in 2.0 but samples run on 2.1
Foundational ASP.NET Core 2.1 Samples 136 2.1

How to run these samples

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

Most of the examples here uses Microsoft.AspNetCore package which is a package consisted of

  Microsoft.AspNetCore.Diagnostics
  Microsoft.AspNetCore.HostFiltering
  Microsoft.AspNetCore.Hosting
  Microsoft.AspNetCore.Routing
  Microsoft.AspNetCore.Server.IISIntegration
  Microsoft.AspNetCore.Server.Kestrel
  Microsoft.AspNetCore.Server.Kestrel.Https
  Microsoft.Extensions.Configuration.CommandLine
  Microsoft.Extensions.Configuration.EnvironmentVariables
  Microsoft.Extensions.Configuration.FileExtensions
  Microsoft.Extensions.Configuration.Json
  Microsoft.Extensions.Configuration.UserSecrets
  Microsoft.Extensions.Logging
  Microsoft.Extensions.Logging.Configuration
  Microsoft.Extensions.Logging.Console
  Microsoft.Extensions.Logging.Debug

When an example requires packages that are not listed here, it will be added to the project file.

Foundation ASP.NET Core 2.1 Samples

All these projects require the following dependencies

   "Microsoft.AspNetCore" : "2.1.0"

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

We go deep into Microsoft.AspNetCore.Routing library that provides 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 (12)

We will explore all aspect of middleware building in this section.

  • Middleware 1

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

  • Middleware 2

    As a general rule, only one of your Middleware should write to Response in an execution path. This sample shows how to work around this by buffering the Response.

    e.g.

    If path / involves the execution of Middleware 1, Middleware 2 and Middleware 3, only one of these should write to Response.

  • 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.

  • Middleware 10

    Demonstrate that a middleware is a singleton.

  • Middleware 11

    This sample is similar to Middleware 10 except that this one implement IMiddleware to create Factory-based middleware activation. This means that you can create a middleware that is not a singleton (either Transient or Scoped).

  • Middleware 12

    Contrast the usage of MapWhen (which branch execution) and UseWhen (which doesn't branch execution) in configuring your Middleware.

    • Features (9)

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.

  • Server Addresses Feature - 2

    Use IServer interface to access server addressess when you don't have access to IApplicationBuilder.

  • 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": "2.1.0".

  • 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" : "2.1.0-"`.

  • Maximum Request Body Size Feature

    Use this feature to read and set maximum HTTP Request body size.

    • Dependency Injection (2)

ASP.NET Corenetcore lives and die by DI. It relies on Microsoft.Extensions.DependencyInjection library.

  • 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

These samples depends on Microsoft.Extensions.Caching.Memory library.

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" : "2.1.0".

  • Configuration - INI file - Options

    Read from INI file (with nested keys) and IOptions. It requires taking two new dependencies, "Microsoft.Extensions.Configuration.INI" : "2.1.0" and "Microsoft.Extensions.Options.ConfigurationExtensions" : "2.1.0".

  • Configuration - XML file

    Read from XML file. It requires taking a new dependency, "Microsoft.Extensions.Configuration.Xml" : "2.1.0".

    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" : "2.1.0" and "Microsoft.Extensions.Options.ConfigurationExtensions" : "2.1.0".

    • Localization and Globalization (6)

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": "2.1.0" and "Microsoft.Extensions.Localization": "2.1.0".

  • 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.

  • Localization - 5

    Demonstrate using Portable Object (PO) files to support localization instead of the cumbersome resx file. This sample requires OrchardCore.Localization.Core package. This sample requires ASPNET Core 2.

  • Localization - 6

    This is a continuation of previous sample but with context, which allows the same translation key to return different strings.

    • 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 an additional "Microsoft.AspNetCore.Rewrite" : "2.1.0-*" dependency.

    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": "2.1.0.

  • 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(6)

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).

  • Middleware Analysis

    Here we go into the weeds of analysing middlewares in your request pipeline. This is a bit complicated. It requires the following packages:

    • Microsoft.AspNetCore.MiddlewareAnalysis
    • Microsoft.Extensions.DiagnosticAdapter
    • Microsoft.Extensions.Logging.Console
    • Static Files(6)

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

  • Serve static files

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

    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.

  • Allow Directory Browsing

    Allow listing and browsing of your wwwroot folder.

  • Use File Server

    Combines the functionality of UseStaticFiles, UseDefaultFiles, and UseDirectoryBrowser.

  • Custom Directory Formatter

    Customize the way Directory Browsing is displayed. In this sample the custom view only handles flat directory. We will deal with more complex scenario in the next sample.

  • Custom Directory Formatter - 2

    Show custom Directory Browsing and handle directory listing as well as files.

  • Allow Directory Browsing

    Use Directory Browsing on a certain path using DirectoryBrowserOptions.RequestPath, e.g. /browse.

    • Web Sockets (5)

We are going to explore websocket functionality provided by ASP.NET Core. All the samples here require Microsoft.AspNetCore.WebSockets.

Warning: These samples are low level websocket code. For production, use SignalR. Yes I will work on SignalR samples soon.

  • Echo Server

    This is the simplest web socket code you can write. It simply returns what you sent. It does not handle the closing of the connection. It does not handle data that is larger than buffer. It only handles text payload.

  • Echo Server 2

    We improve upon the previous sample by adding console logging (requiring Microsoft.Extensions.Logging.Console package) and handling data larger than the buffer. I set the buffer to be very small (4 bytes) so you can see how it works.

  • Echo Server 3

    We improve upon the previous sample by enabling broadcast. What you see here is a very crude chat functionality.

  • Echo Server 4

    We improve upon the previous sample by handling closing event intiated by the web client.

  • Chat Server

    Implement a rudimentary single channel chat server.

    • Server-Sent Events (1)
  • Forever Server

    This server will send a 'hello world' greeting forever.

    • Syndications (2)

We are using the brand new Microsoft.SyndicationFeed.ReaderWriter package to read RSS and ATOM feeds.

  • Syndication - Read RSS

    This is the shortest amount of code to read an RSS feed. This example read the feed from the inventor of RSS, Dave Winer at http://scripting.com/rss.xml.

  • Syndication - Read RSS with extensions

    This sample process RSS Outline Extension.

    • Utils(3)
  • Status Codes

    Here we contrast between the usage of Microsoft.AspNetCore.Http.StatusCodes and System.Net.HttpStatusCode.

  • MediaTypeNames

    This class provides convenient constants for some common MIME types. It's not extensive by any means however MediaTypeNames.Text.Html and MediaTypeNames.Application.Json come handy.

  • MediaTypeNames - 2

    Using FileExtensionContentTypeProvider to obtain the correct MIME type of a filename extension.

    • Misc (3)
  • 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 "Markdig" : "0.15.1" 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 "Markdig" : "0.15.1" 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": "2.1.0" to enable this functionality.

    • Web Utilities(3)

This section shows various functions avaiable at Microsoft.AspNetCore.WebUtilities.

  • Query Helpers

    This utility helps you generate query string for your url safely (ht Rehan Saeed).

  • Parse Query String

    QueryHelpers.ParseQuery allows you to parse a raw query string and access its individual key and values.

  • Reason Phrases

    This utility returns HTTP response phrases given a status code number.

    • Uri Helper(5)

This section shows various methods available at Microsoft.AspNetCore.Http.Extensions.UriHelper.

  • Get Display Url

    Request.GetDisplayUrl() shows complete url with host, path and query string of the current request. It's to be used for display purposes only.

  • Get Encoded Url

    Request.GetEncodedUrl() returns the combined components of the request URL in a fully escaped form suitable for use in HTTP headers and other HTTP operations.

  • Get Encoded Path and Query

    UriHelper.GetEncodedPathAndQuery returns the relative URL of a request.

  • From Absolute

    UriHelper.FromAbsolute separates the given absolute URI string into components.

  • Build Absolute

    UriHelper.BuildAbsolute combines the given URI components into a string that is properly encoded for use in HTTP headers. This sample shows 9 ways on how to use it.

    • Trimming (1)

This section shows the various way on how to trim the size of your application by using Microsoft.Packagin.Tools.Trimming

  • Trimming Microsoft.AspNetCore.All hello world application

    Run dotnet publish or dotnet build and read the output in your terminal. It will read something similar to Trimmed 115 out of 168 files for a savings of 18.93 MB Final app size is 3.07 MB. You can turn off the trimming by setting <TrimUnusedDependencies>true</TrimUnusedDependencies> to false at the project file.

    • Email (1)

This section shows samples of using MailKit, which is essentially the library to use for sending and receiving email in ASP.NET Core.

  • Send email

    This shows an example on how to send an email using SMTP.

    Thanks to @Kinani95.

  • Keeping track of anonymous users

    Keep track of anonymous user in your ASP.NET Core (useful in scenario such as keeping track of shopping cart) using ReturnTrue.AspNetCore.Identity.Anonymous library.

    • Middleware (1)
  • Response Buffering

    Use Microsoft.AspNetCore.Buffering 0.2.2 middleware to implement response buffering facility. This will allow you to change your response after you write them.

    • Device Detection (1)

The samples in this section rely on Wangkanai.Detection library.

  • Device Detection

    This is the most basic device detection. You will be able to detect whether the client is a desktop or a mobile client.

    • Owin (1)

All these samples require Microsoft.AspNetCore.Owin package. These are low level samples and in most cases are not relevant to your day to day ASP.NET Core development.

  • Owin

    Hello world the hard way.

    • Image Sharp (1)

All these samples require SixLabors.ImageSharp.Web middleware package. This middleware is an excelent tool to process your day to day image processing need.

  • Image-Sharp

    This example shows how to enable image resizing functionality to your site. It's super easy and the middleware takes care of caching, etc.

Generic Host (9)

Generic Host is an awesome way to host all sort of long running tasks and applications, e.g. messaging, background tasks, etc.

This section is dedicated to all the nitty gritty of Generic Host. All the examples in this section rely on Microsoft.AspNetCore.App package.

Other resources

These are other aspnetcore resources with code samples

Misc