Building a C# Cmdlet with Visual Studio

This document describes steps for building a C# Cmdlet with Visual Studio in 2 ways:

Building a C# Cmdlet for PowerShell Core
Building a C# Cmdlet for PowerShell Standard 3.0

Building a C# Cmdlet for PowerShell Core with Visual Studio

This demonstrates how to build your own C# cmdlet for PowerShell Core with Visual Studio. Targeting for PowerShell Core means that the cmdlet may not work against Windows PowerShell if you take dependencies on new APIs introduced in PowerShell Core.

We will use the free Visual Studio Community 2017.

When installing Visual Studio 2017 select .NET Core cross-platform development under Other Toolsets
Create new C# project SendGreeting of type Class Library (.NET Core)
Now we need to setup PowerShell Core reference assemblies. In Solution Explorer right click on project Dependencies and select Manage NuGet Packages... In the top-right corner of the package manager click on the small Settings sprocket icon that is to the right from Package source dropdown. By default, there will be only nuget.org package source in Available package sources list. Add another package source with name powershell-core and source https://powershell.myget.org/F/powershell-core/api/v3/index.json
In the package manager select new powershell-core in Package source dropdown, select Browse tab, type in System.Management.Automation in the search and select Include prerelease. It should find System.Management.Automation package, select it and it will show package details; install it using Install button.

Add the code of cmdlet:

using System.Management.Automation;  // PowerShell namespace.

namespace SendGreeting
{
    // Declare the class as a cmdlet and specify and
    // appropriate verb and noun for the cmdlet name.
    [Cmdlet(VerbsCommunications.Send, "Greeting")]
    public class SendGreetingCommand : Cmdlet
    {
        // Declare the parameters for the cmdlet.
        [Parameter(Mandatory = true)]
        public string Name { get; set; }

        // Overide the ProcessRecord method to process
        // the supplied user name and write out a
        // greeting to the user by calling the WriteObject
        // method.
        protected override void ProcessRecord()
        {
            WriteObject("Hello " + Name + "!");
        }
    }
}

At this point everything should look like this:

Build solution (F6); The Output window will print the location of generated cmdlet DLL:
Start PowerShell Core, run Import-Module on DLL path from previous step and run cmdlet: You can also run the same cmdlet on Linux and other systems that PowerShell Core supports:

Building a C# Cmdlet for PowerShell Standard 3.0 with Visual Studio

Steps below show how to build your own C# cmdlet for PowerShell Standard 3.0 with Visual Studio. Targeting PowerShell Standard 3.0 means that the same module will work against PowerShell Core as well as Windows PowerShell v3 and newer, however, you are limited to a subset of the available PowerShell APIs.