Run PowerShell as 32-bit or 64-bit from C#

Question

I build a 32-bit .NET DLL that executes PowerShell scripts. I need it to be able to run scripts alternatively as 64-bit and 32-bit.

I already know how to do it with the command line:

C:\Windows\Sysnative\cmd /c powershell -ExecutionPolicy ByPass "& 'script.ps1' arguments"
C:\Windows\SysWOW64\cmd /c powershell -ExecutionPolicy ByPass "& 'script.ps1' arguments"

But I need to be able to use the interface to C#, with either the System.Management.Automation.PowerShell class or the System.Management.Automation.Runspaces.Pipeline class, in order to asynchronously collect outputs from the script.

Answer 1

The comment from @PetSerAl is the solution. With an out of process runspace, I can change the bitness.

I copy his code here:

using System;
using System.Management.Automation;
using System.Management.Automation.Runspaces;
public static class TestApplication {
    public static void Main() {
        Console.WriteLine(Environment.Is64BitProcess);
        using(PowerShellProcessInstance pspi = new PowerShellProcessInstance()) {
            string psfn = pspi.Process.StartInfo.FileName;
            psfn=psfn.ToLowerInvariant().Replace("\\syswow64\\", "\\sysnative\\");
            pspi.Process.StartInfo.FileName=psfn;
            using(Runspace r = RunspaceFactory.CreateOutOfProcessRunspace(null, pspi)) {
                r.Open();
                using(PowerShell ps = PowerShell.Create()) {
                    ps.Runspace=r;
                    ps.AddScript("[Environment]::Is64BitProcess");
                    foreach(PSObject pso in ps.Invoke()) {
                        Console.WriteLine(pso);
                    }
                }
            }
        }
    }
}