• ASP.NET 5

ASP.NET 5 Applications with VS Code

Note: ASP.NET 5 and DNX (the .NET Execution Environment) on OS X and Linux are in an early Beta/Preview state. This guide will help you get started but we recommend following the aspnet Home project on GitHub for the latest information.


ASP.NET 5/DNX is a lean .NET stack for building modern cloud and web apps that run on OS X, Linux, and Windows. It has been built from the ground up to provide an optimized development framework for apps that are either deployed to the cloud or run on-premises. It consists of modular components with minimal overhead, so you retain flexibility while constructing your solutions.

Installing ASP.NET 5 and DNX

Installation for each platform is slightly different, please refer to the following setup instructions based on your operating system. - OS X - Linux - Windows

Tip: Add the following to your .bash_profile and restart the Terminal. The first line will ensure that you can always run the dnvm and dnu commands. The second line works around a known bug in Mono where you may see the IOException FileSystemWatcher has reached the maximum number of files to watch when running your application.

source dnvm.sh
export MONO_MANAGED_WATCHER=disabled

After you edit .bash_profile, make sure that you then run the following command:

dnvm upgrade

Getting Started

If you don't have an existing ASP.NET DNX application, we recommend using yeoman to scaffold a new one. Presuming you have Node.js installed, simply npm install yeoman and supporting tools such as the asp.net generator, gulp, and bower. This can be done in one command:

npm install -g yo generator-aspnet gulp bower

Scaffolding your first Application

From the terminal, run yo aspnet to start the generator. Follow the prompts and pick the Web Application

Scaffold a new ASP.NET 5 Application

Follow the instructions provided by the generator, go to the WebApplication folder and run dnu restore to install of the necessary NuGet packages to run the application.

cd WebApplication
dnu restore

The ASP.NET 5 docs do a great job describing how to build next generation Cloud and Web applications so we won't do that here. Instead, we will focus on what Visual Studio Code can do.

Projects and Project Selection

VS Code is file and folder based as compared to Visual Studio, which is project or solution based. You don't open a solution in VS Code, you simply open a folder and if a supported project exists we will load it.

Open the WebApplication folder. If you set up a shortcut as described in setup, you can simply run code . from the terminal.

The ASP.NET 5/DNX project system is also file and folder based, so when VS Code sees the project.json it will load it. If you have multiple project.json files you can pick which one you want to use, looks down in the status bar.

DNX commands in palette

Notice the project indication on the lower left corner. When the icon is flashing, OmniSharp (the brain behind VS Code’s C# support) is starting, loading your project. If you see a red icon, it means something went wrong, you can find out by looking at the OmniSharp Output Log (kb(o.showOutput)).

When the status bar shows the project information it’s a good time to get going. You can now leverage the full power of VS Code, author code and run your app.

Startup.cs is the startup file for your newly scaffolded application. Find the Startup method and let's start writing code. As soon as you access the framework (or any class in your application) you will get a rich IntelliSense experience, including parameter tool tips and the ability to cycle through overloads.

DNX commands in palette

Commands with Ease

The project.json file allows you to define commands for your projects. Those commands are understood by Visual Studio Code, and they will show up in the Command Palette.

There are 2 commands defined in our application:

DNX commands

To execute these commands you could run them from the terminal, but a faster way is to open the Command Palette (kb(workbench.action.showCommands)) in VS Code, type dnx, and select the dnx: Run Command option:

DNX run commands in Command Palette

Next, select the option corresponding to the DNX command to be executed:

DNX commands in palette

In this walkthrough we want to run the website, so the command we want to run is dnx: web. VS Code understands the configured DNX runtime and will open a console window, and execute the command in there.

Open your favorite browser and browse to http://localhost:5000 to browse the site we created.

Note: command execution from the Command Palette doesn’t work yet on Linux. To run commands manually on Linux, start a console and type: dnx <command_name>.


Visual Studio Code and ASP.NET 5 are in preview and at this time debugging ASP.NET 5 is not supported in Visual Studio Code (on any platform). Rest assured, we are working hard to bring these experiences to you in the near future.

Next Steps

We hope this gets you started building ASP.NET 5 applications. Try these things next: Editing Evolved - Lint, IntelliSense, Lightbulbs, Peek and Goto Definition and more Tasks - Running tasks with Gulp, Grunt and Jake. Showing Errors and Warnings