Get Powershell command's output when invoked through code

Question

I have written a piece of code (in C#) to execute a Powershell script (specifically Azure PowerShell) using System.Management.Automation. The powershell script basically uploads a vhd in a container on Azure, which shows the upload progress and time elapsed etc when command is manually entered through azure Powershell. Through code everything works fine but i want to get the result/output of a command (i.e. upload progress, time elapsed), during command execution (i.e. pipeline.invoke();) here is the code:

 RunspaceConfiguration runspaceConfiguration = RunspaceConfiguration.Create();
 Runspace runspace = RunspaceFactory.CreateRunspace(runspaceConfiguration);
 runspace.Open();
 RunspaceInvoke scriptInvoker = new RunspaceInvoke(runspace);
 Pipeline pipeline = runspace.CreatePipeline();

 Command myCommand = new Command(scriptPath);
 foreach (var argument in arguments)
 {
     myCommand.Parameters.Add(new CommandParameter(argument.Key, argument.Value));
 }
 pipeline.Commands.Add(myCommand);

 var results = pipeline.Invoke(); // i want to get results here (i.e. during command execution) 
 foreach (var psObject in results)
 {
     System.Diagnostics.Debug.Write(psObject.BaseObject.ToString());
 }

Please guide if it is possible to retrieve live output from Powershell.

Answer 1

Unless you're targeting PowerShell 1.0, there's no need to set up your runspace and pipeline manually, create an instance of the PowerShell class instead:

PowerShell psinstance = PowerShell.Create();
psinstance.AddScript(scriptPath);
var results = psinstance.Invoke();

Way simpler.

---

Now, the PowerShell class exposes the various non-standard output streams (Verbose, Debug, Error etc.) - including the Progress Stream - via the Streams property so you can subscribe to it, like so:

psinstance.Streams.Progress.DataAdded += myProgressEventHandler;

And then in your event handler:

static void myProgressEventHandler(object sender, DataAddedEventArgs e)
{
    ProgressRecord newRecord = ((PSDataCollection<ProgressRecord>)sender)[e.Index];
    if (newRecord.PercentComplete != -1)
    {
        Console.Clear();
        Console.WriteLine("Progress updated: {0}", newRecord.PercentComplete);
    }
}

---

As an example, here is that event handler shown above in action, while running a sample script that writes progress information (sample script posted below) in a simple console application:

Test-Progress.ps1

function Test-Progress
{
    param()

    Write-Progress -Activity 'Testing progress' -Status 'Starting' -PercentComplete 0
    Start-Sleep -Milliseconds 600
    1..10 |ForEach-Object{
        Write-Progress -Activity "Testing progress" -Status 'Progressing' -PercentComplete $(5 + 6.87 * $_)
        Start-Sleep -Milliseconds 400
    }
    Write-Progress -Activity 'Testing progress' -Status 'Ending' -PercentComplete 99
    Start-Sleep -Seconds 2
    Write-Progress -Activity 'Testing progress' -Status 'Done' -Completed
}

Test-Progress

Answer 2

It may be a little late, but still.

@Mathias R. Jessen answer works great, but for cases with the output of ordinary strings (without Write-Progress and so on):

Initialize the collection first

PSDataCollection<PSObject> output = new PSDataCollection<PSObject>();
output.DataAdded += Output_DataAdded;

Perform

var res = psinstance.BeginInvoke<PSObject, PSObject>(null, output);
res.AsyncWaitHandle.WaitOne();

Get the result real-time

private static void Output_DataAdded(object sender, DataAddedEventArgs e)
{
    PSObject newRecord = ((PSDataCollection<PSObject>)sender)[e.Index];
    Console.WriteLine(newRecord);
}

Tested on Get-Process PS command.