Importing and Invoking a Windows PowerShell Workflow

Windows PowerShell 3, allows you to import and invoke a workflow that is packaged as a Windows PowerShell module. For information about Windows PowerShell modules, see Writing a Windows PowerShell Module.

The System.Management.Automation.Psjobproxyclass is used as a client side proxy for workflow objects on the server. The following procedure explains how to use a System.Management.Automation.Psjobproxyobject to invoke a workflow.

Creating a PSJobProxy object to execute workflow commands on a remote server.

  1. Create an System.Management.Automation.Runspaces.Wsmanconnectioninfoobject to create a connection to a remote runspace.

  2. Set the System.Management.Automation.Runspaces.Wsmanconnectioninfo.Shelluri* property of the System.Management.Automation.Runspaces.Wsmanconnectioninfoobject to Microsoft.PowerShell.Workflow to specify a Windows PowerShell endpoint.

  3. Create a runspace that uses the connection created by completing the previous steps.

  4. Create a System.Management.Automation.Powershellobject and set its System.Management.Automation.Powershell.Runspace* property to the runspace created in the previous step.

  5. Import the workflow module and its commands into the System.Management.Automation.Powershell.

  6. Create a System.Management.Automation.Psjobproxy object and use it to execute workflow commands on the remote server.

Example

The following code example demonstrates how to invoke a workflow by using Windows PowerShell.

This example requires Windows PowerShell 3.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Management.Automation;
using System.Management.Automation.Runspaces;

namespace WorkflowHostTest
{

class Program
    {
        static void Main(string[] args)
        {
            if (args.Length == 0)
            {
                Console.WriteLine("Specify path to Workflow module");
                return;
            }

            string moduleFile = args[0];

            Console.Write("Creating Remote runspace connection...");
            WSManConnectionInfo connectionInfo = new WSManConnectionInfo();

            //Set the shellURI to workflow endpoint Microsoft.PowerShell.Workflow
            connectionInfo.ShellUri = "Microsoft.PowerShell.Workflow";

            //Create and open a runspace.
            Runspace runspace = RunspaceFactory.CreateRunspace(connectionInfo);
            runspace.Open();
            Console.WriteLine("done");

            PowerShell powershell = PowerShell.Create();
            powershell.Runspace = runspace;
            Console.Write("Setting $VerbosePreference=\"Continue\"...");
            powershell.AddScript("$VerbosePreference=\"Continue\"");
            powershell.Invoke();
            Console.WriteLine("done");

            Console.Write("Importing Workflow module...");
            powershell.Commands.Clear();

            //Import the module in to the PowerShell runspace. A XAML file could also be imported directly by using Import-Module.
            powershell.AddCommand("Import-Module").AddArgument(moduleFile);
            powershell.Invoke();
            Console.WriteLine("done");

            Console.Write("Creating job proxy...");
            powershell.Commands.Clear();
            powershell.AddCommand("Get-Proc").AddArgument("*");
            PSJobProxy job = powershell.AsJobProxy();
            Console.WriteLine("done");

                Console.WriteLine();
                Console.WriteLine("Using job proxy and performing operations...");
                Console.WriteLine("State of Job :" + job.JobStateInfo.State.ToString());
                Console.WriteLine("Starting job...");
                job.StartJob();
                Console.WriteLine("State of Job :" + job.JobStateInfo.State.ToString());

                // use blocking enumerator to wait for objects until job finishes
                job.Output.BlockingEnumerator = true;
                foreach (PSObject o in job.Output)
                {
                    Console.WriteLine(o.Properties["ProcessName"].Value.ToString());
                }

                // wait for a random time before attempting to stop job
                Random random = new Random();
                int time = random.Next(1, 10);
                Console.Write("Sleeping for {0} seconds when job is running on another thread...", time);
                System.Threading.Thread.Sleep(time * 1000);
                Console.WriteLine("done");
                Console.WriteLine("Stopping job...");
                job.StopJob();
                Console.WriteLine("State of Job :" + job.JobStateInfo.State.ToString());
                Console.WriteLine();
                job.Finished.WaitOne();
                Console.WriteLine("Output from job");
                Console.WriteLine("---------------");

                foreach (PSObject o in job.Output)
                {
                    Console.WriteLine(o.Properties["ProcessName"].Value.ToString());
                }

                Console.WriteLine();
                Console.WriteLine("Verbose messages from job");
                Console.WriteLine("-------------------------");
                foreach (VerboseRecord v in job.Verbose)
                {
                    Console.WriteLine(v.Message);
                }

            runspace.Close();
        }
    }
}