How to pass a parameter from C# to a PowerShell script file? - powershell

Question

From the command line I can do.
.\test.ps1 1
How do I pass the parameter when doing this from C#?
I've tried
.AddArgument(1)
.AddParameter("p", 1)
And I have tried passing values in as IEnumerable<object> in the .Invoke() but $p does not get the value.
namespace ConsoleApplication1
{
using System;
using System.Linq;
using System.Management.Automation;
class Program
{
static void Main()
{
// Contents of ps1 file
// param($p)
// "Hello World ${p}"
var script = #".\test.ps1";
PowerShell
.Create()
.AddScript(script)
.Invoke().ToList()
.ForEach(Console.WriteLine);
}
}
}

Answer 1

How's this?
static void Main()
{
string script = #"C:\test.ps1 -arg 'hello world!'";
StringBuilder sb = new StringBuilder();
PowerShell psExec = PowerShell.Create();
psExec.AddScript(script);
psExec.AddCommand("out-string");
Collection<PSObject> results;
Collection<ErrorRecord> errors;
results = psExec.Invoke();
errors = psExec.Streams.Error.ReadAll();
if (errors.Count > 0)
{
foreach (ErrorRecord error in errors)
{
sb.AppendLine(error.ToString());
}
}
else
{
foreach (PSObject result in results)
{
sb.AppendLine(result.ToString());
}
}
Console.WriteLine(sb.ToString());
}
Here's a similar version that passes an instance of a DateTime
static void Main()
{
StringBuilder sb = new StringBuilder();
PowerShell psExec = PowerShell.Create();
psExec.AddCommand(#"C:\Users\d92495j\Desktop\test.ps1");
psExec.AddArgument(DateTime.Now);
Collection<PSObject> results;
Collection<ErrorRecord> errors;
results = psExec.Invoke();
errors = psExec.Streams.Error.ReadAll();
if (errors.Count > 0)
{
foreach (ErrorRecord error in errors)
{
sb.AppendLine(error.ToString());
}
}
else
{
foreach (PSObject result in results)
{
sb.AppendLine(result.ToString());
}
}
Console.WriteLine(sb.ToString());
}

Answer 2

So, to make a long answer short: Use AddCommand instead of AddScript

Answer 3

another way is to fill the runspace with variables.
public static string RunPs1File(string filePath, Dictionary<string, object> arguments)
{
var result = new StringBuilder();
using (Runspace space = RunspaceFactory.CreateRunspace())
{
space.Open();
foreach (KeyValuePair<string, object> variable in arguments)
{
var key = new string(variable.Key.Where(char.IsLetterOrDigit).ToArray());
space.SessionStateProxy.SetVariable(key, variable.Value);
}
string script = System.IO.File.ReadAllText(filePath);
using (PowerShell ps1 = PowerShell.Create())
{
ps1.Runspace = space;
ps1.AddScript(script);
var psOutput = ps1.Invoke();
var errors = ps1.Streams.Error;
if (errors.Count > 0)
{
var e = errors[0].Exception;
ps1.Streams.ClearStreams();
throw e;
}
foreach (var line in psOutput)
{
if (line != null)
{
result.AppendLine(line.ToString());
}
}
}
}
return result.ToString();
}

Answer 4

Currently a simpler solution is to read the script as a string first.
PowerShell
.Create()
.AddScript(File.ReadAllText(script)).AddParameter("p", 1)
.Invoke().ToList()
.ForEach(Console.WriteLine);