Mixing C# source code with PowerShell script code to speed your development

I had some C# code ready but needed to use it inside a PowerShell script.

At StackOverflow I found some code that put me in the right path. So here's a practical example when mixing codes inside a PowerShell script file:

. ".\Invoke-Parallel.ps1" # Importing another script into this PowerShell script file

$csharpSource = @"

using System;
using System.Collections.Generic;
using System.Linq;

public class DateExtensions
     public static List<Tuple<DateTime, DateTime>> GetWeeksBetweenDates(DateTime startDate, DateTime endDate)
        var weeks = new List<Tuple<DateTime, DateTime>>();
         for (DateTime date = startDate; date <= endDate; date = date.AddDays(8))
            var weekEnd = date.AddDays(7);
            weeks.Add(new Tuple<DateTime, DateTime>(date, weekEnd <= endDate ? weekEnd : endDate));

        return weeks;

Add-Type -TypeDefinition $csharpSource # Includes the C# code defined above to be called through the PowerShell script

$appPath = "C:\SomeFolder"
$startDate = [datetime]'6/1/2017'
$endDate = [datetime]'5/5/2018'

$weeks = [DateExtensions]::GetWeeksBetweenDates($startDate, $endDate)

#Calls MyApp in batches, that is, for each week...
$weeks | Invoke-Parallel -ImportVariables -ScriptBlock {   
    Set-Location -Path $appPath
    $date = [string]::Format("{0:yyyyMMdd},{1:yyyyMMdd}", $_.Item1, $_.Item2)

    #Write-Host $date

    dotnet MyApp.dll budat=$date cpudt=$date # Calls .NET Core "executable" DLL for each week

pause #Keeps PowerShell window open to see the results

As we see in the code above, the variable $csharpSource holds the C# source code that later will called in the PowerShell script.

We then add\mix the C# code to\with PowerShell with the command Add-Type passing to it the $csharpSource variable that holds the source code. Simple as that.

Inside PowerShell script code we call the method defined in C# code with:

$weeks = [DateExtensions]::GetWeeksBetweenDates($startDate, $endDate)

This is pretty useful because we don't need to convert our C# code to PowerShell idiom.

Hope it helps.

How to convert C# code to a PowerShell Script?