running powershell script with parameters with vb.net - vb.net

Question

i have a powershell script that i want to kick off with vb.net code, however when it gets to the part where i invoke the pipeline i get the error "Cannot process command because of one or more missing mandatory parameters: District County FMS."
the powershell script is very simple, it takes 3 parameters and write-host's the param values back to the shell. pretty much my question is, how do i make it work? thank you everyone for you time.
vb.net(the other professionals i work with have boiled the error down to 'get-process' not being the right command for my scriptParams variable, but we're not sure which command to use)
Sub Main()
Console.WriteLine(RunScript(LoadScript(Directory.GetCurrentDirectory() + "/CreateProject.ps1 ")))
Console.ReadLine()
End Sub
Private Function RunScript(ByVal scriptText As String) As String
' create Powershell runspace
Dim MyRunSpace As Runspace = RunspaceFactory.CreateRunspace()
' open it
MyRunSpace.Open()
' create a pipeline and feed it the script text
Dim MyPipeline As Pipeline = MyRunSpace.CreatePipeline()
MyPipeline.Commands.AddScript(scriptText)
' add an extra command to transform the script output objects into nicely formatted strings
' remove this line to get the actual objects that the script returns. For example, the script
' "Get-Process" returns a collection of System.Diagnostics.Process instances.
MyPipeline.Commands.Add("Out-String")
'[ay]create a command object by bassing the command to the constructor
Dim scriptParams As New Command("get-process")
'[ay]pass parameters to the command
scriptParams.Parameters.Add("District", "D1")
scriptParams.Parameters.Add("County", "Lee")
scriptParams.Parameters.Add("FMS", "101000")
MyPipeline.Commands.Add(scriptParams)
' execute the script
Dim results As Collection(Of PSObject) = MyPipeline.Invoke()
' close the runspace
MyRunSpace.Close()
' convert the script result into a single string
Dim MyStringBuilder As New StringBuilder()
For Each obj As PSObject In results
MyStringBuilder.AppendLine(obj.ToString())
Next
' return the results of the script that has
' now been converted to text
Return MyStringBuilder.ToString()
End Function
Private Function LoadScript(ByVal filename As String) As String
Try
' Create an instance of StreamReader to read from our file.
' The using statement also closes the StreamReader.
Dim sr As New StreamReader(filename)
' use a string builder to get all our lines from the file
Dim fileContents As New StringBuilder()
' string to hold the current line
Dim curLine As String = ""
' loop through our file and read each line into our
' stringbuilder as we go along
Do
' read each line and MAKE SURE YOU ADD BACK THE
' LINEFEED THAT IT THE ReadLine() METHOD STRIPS OFF
curLine = sr.ReadLine()
fileContents.Append(curLine + vbCrLf)
Loop Until curLine Is Nothing
' close our reader now that we are done
sr.Close()
' call RunScript and pass in our file contents
' converted to a string
Return fileContents.ToString()
Catch e As Exception
' Let the user know what went wrong.
Dim errorText As String = "The file could not be read:"
errorText += e.Message + "\n"
Return errorText
End Try
End Function
PowerShell
[CmdletBinding()]
Param(
[Parameter(Mandatory = $True)]
[string]$District,
[Parameter(Mandatory = $True)]
[string]$County,
[Parameter(Mandatory = $True)]
[string]$FMS
)
Write-Host "District: $Dsistrict"
Write-Host "County: $County"
Write-Host "FMS: $FMS"

Answer 1

These examples are in C#, but it's the same API.
https://blogs.msdn.microsoft.com/kebab/2014/04/28/executing-powershell-scripts-from-c/
More C# examples, but these are using the RunspaceFactory API you already have in your pipeline.
Execute PowerShell Script from C# with Commandline Arguments

Answer 2

I'm new to PowerShell but may this help you
in your code
scriptParams.Parameters.Add("District", "D1")
scriptParams.Parameters.Add("County", "Lee")
scriptParams.Parameters.Add("FMS", "101000")
MyPipeline.Commands.Add(scriptParams)
I think this ADD new params to your script so value for already exit params not set
You need to pass param values to your script not add new param

Answer 3

I know this is an old question but there was no good answer and I just spent too long getting this to work to not share my knowledge.
In the VB code, you'd remove the following:
MyPipeline.Commands.AddScript(scriptText)
MyPipeline.Commands.Add("Out-String")
Then, in place of the Out-String addition, add:
Dim myCommand As Command = New Command(scriptText, True)
' Add your parameters here.
' Obviously you can add variables instead of static strings if needed.
myCommand.Parameters.Add("District", "D1")
myCommand.Parameters.Add("County", "Lee")
myCommand.Parameters.Add("FMS", "101000")
' You can add switches in this manner as well. For example, a switch "I"
' You need to include the - with switches
myCommand.Parameters.Add("-i")
' Finally, apply your command object to the pipeline and proceed as normal
MyPipeline.Commands.Add(myCommand)