How to: Create a Custom Tracking Participant

using System.Activities.Tracking;
using System.IO;

class StatusTrackingParticipant : TrackingParticipant
{
}

protected override void Track(TrackingRecord record, TimeSpan timeout)
{
    ActivityStateRecord asr = record as ActivityStateRecord;

    if (asr != null)
    {
        if (asr.State == ActivityStates.Executing &&
            asr.Activity.TypeName == "System.Activities.Statements.WriteLine")
        {
            // Append the WriteLine output to the tracking
            // file for this instance
            using (StreamWriter writer = File.AppendText(record.InstanceId.ToString()))
            {
                writer.WriteLine(asr.Arguments["Text"]);
                writer.Close();
            }
        }
    }
}

using System.Activities.Tracking;

// Add the custom tracking participant with a tracking profile
// that only emits tracking records for WriteLine activities.
StatusTrackingParticipant stp = new StatusTrackingParticipant
{
    TrackingProfile = new TrackingProfile
    {
        Queries = 
        {
            new ActivityStateQuery
            {
                ActivityName = "WriteLine",
                States = { ActivityStates.Executing },
                Arguments = { "Text" }
            }
        }
    }
};

wfApp.Extensions.Add(stp);

private void ConfigureWorkflowApplication(WorkflowApplication wfApp)
{
    // Configure the persistence store.
    wfApp.InstanceStore = store;

    // Add a StringWriter to the extensions. This captures the output
    // from the WriteLine activities so we can display it in the form.
    StringWriter sw = new StringWriter();
    wfApp.Extensions.Add(sw);

    // Add the custom tracking participant with a tracking profile
    // that only emits tracking records for WriteLine activities.
    StatusTrackingParticipant stp = new StatusTrackingParticipant
    {
        TrackingProfile = new TrackingProfile
        {
            Queries = 
            {
                new ActivityStateQuery
                {
                    ActivityName = "WriteLine",
                    States = { ActivityStates.Executing },
                    Arguments = { "Text" }
                }
            }
        }
    };

    wfApp.Extensions.Add(stp);

    // Workflow lifecycle handlers...

// If there is tracking data for this workflow, display it
// in the status window.
if (File.Exists(WorkflowInstanceId.ToString()))
{
    string status = File.ReadAllText(WorkflowInstanceId.ToString());
    UpdateStatus(status);
}

private void InstanceId_SelectedIndexChanged(object sender, EventArgs e)
{
    if (InstanceId.SelectedIndex == -1)
    {
        return;
    }

    // Clear the status window.
    WorkflowStatus.Clear();

    // If there is tracking data for this workflow, display it
    // in the status window.
    if (File.Exists(WorkflowInstanceId.ToString()))
    {
        string status = File.ReadAllText(WorkflowInstanceId.ToString());
        UpdateStatus(status);
    }

    // Get the workflow version and display it.
    // If the workflow is just starting then this info will not
    // be available in the persistence store so do not try and retrieve it.
    if (!WorkflowStarting)
    {
        WorkflowApplicationInstance instance =
            WorkflowApplication.GetInstance(this.WorkflowInstanceId, store);

        WorkflowVersion.Text =
            WorkflowVersionMap.GetIdentityDescription(instance.DefinitionIdentity);

        // Unload the instance.
        instance.Abandon();
    }
}