Before we can start creating a project using .NET Core for RPI3, we first need to explain what and why we use .NET CORE !
.NET Core supports three app models:
- ASP.NET apps and services
- Console apps
- Universal Windows Platform (UWP) apps
First of all .Net CORE is a Cross-Platform Framework opposed to the regular .Net Framework.
Supporting the following platforms:
- Windows
- OS X
- Linux
Read more about .Net Frameworks here
More info you can find here and here
Since RPI3 runs on an ARM architecture we can’t just use Standard .Net Assemblies to build projects…
You can now easily convert a platform-specific class library into a portable class library by publishing to another platform.
I will show you an example as we go along.
Getting Started
As being a scripter I hate to install all the overhead on my PC just to do simple things !
That’s why will only use the Command Line Interface (CLI) and NO Visual Studio 
Prerequisites :
We first have to install the .Net Core SDK on you desktop PC.
At the moment MS has arrived at .Net Core SDK version 2.1.103, Download here
This is all you need to do a quick start
Once installed open the Command Prompt and let’s check the version installed.
Run command : dotnet /? to get all options.
To get the version info we run the command:
dotnet –version or even better is dotnet –info
.Net Core Extensions
In contrast to the .NET Framework, the .NET Core platform will be delivered as a set of NuGet packages.
These extension are needed to build your applications. We will come back to this later on showing the examples…
TIP :
You can download packages manually from the Nuget Site and open them using 7-zip.
And extract the libraries you need for your environment…
As mentioned before instead of using Visual Studio to start our for project.
We will just use the DotNet Core Command line Tools, to build the first Console App in .Net Core for RPI3.
.Net Core has the same Template Apps as you can get through Visual Studio, let’s see what is available.
Run command : dotnet new
Also RAZOR pages are possible as you can see
.Net Core Console App
1. Console app Template :
Run command : dotnet new console
optional parameters are :
–n specifies the name of the project
-o specifies the output location, if omitted it will create the project in the %userprofile% dir.
dotnet new console -n MyFirstCoreApp -o c:\coreiot
The Template app has generated this code
2. Run the console app.
cd c:\coreiot
Dotnet run
dotnet publish -r win8-arm
3. Publish to RPI3
In order to use it on RPI3 or Linux we need to add a few lines in the MyFirstCoreApp.csproj file
<RuntimeFrameworkVersion>2.0.6</RuntimeFrameworkVersion>
<RuntimeIdentifiers>win8-arm;ubuntu.14.04-arm;ubuntu.16.04-arm</RuntimeIdentifiers>
Remember the RuntimeFrameworkVersion you can find in the .Net Core Info see
See dotnet –Info
Next run the dotnet restore command
Next run the dotnet publish -r win8-arm command
or if you focus a Linux distribution you run the command
dotnet publish -r ubuntu.16.04-arm
4. Copy the app to the RPI3
C:\coreiot\bin\Debug\netcoreapp2.0\win8-arm\publish
5. Using PowerShell to run it
cd to your app folder
Runs as expected
6. Change the code using an input parameter
Console.WriteLine(“\nWhat is your name? “);
var name = Console.ReadLine();
var date = DateTime.Now;
Console.WriteLine($”\nHello, {name}, on {date:d} at {date:t}!”);
Console.Write(“\nPress any key to exit…”);
Console.ReadKey(true);
Run command : dotnet run
Next run command : dotnet publish -r win8-arm
And copy it back to RPI3 and test it using PowerShell
Next see here for an SQLite Example on RPI3
Next see here for an ASP .Net Core Example on RPI3
PS :
Keep in mind that for Windows there is a nice Extension Library.
That gives you access to about 20.000 Windows API’s
Run this command to add it to your project
dotnet add package Microsoft.Windows.Compatibility –version 2.0.0
Enjoy !
