Problem with pluggable workflows, getting null

Question

I have this code in the call external method.

private void callExternalMethodActivity1_MethodInvoking(object sender, EventArgs e)

{

callExternalMethodActivitysitename = twInfo.Code;

callExternalMethodActivityurl = workflowProperties.WebUrl;

}

AND the method in the pluggable workflow service has:

public void CreateTrainingSite(string sitename, string url) { //CODE HERE }

When I step into the first method the properties are filled, however when I step into the second method the variables are null.

Please help

---

Edited:

namespace TrainingApprovalSiteWorkflow {

[ExternalDataExchange]
public interface ITrainingSiteCreationService
{
    event EventHandler<CommunicationObjArgs> MessageIn;
    void CreateTrainingSite(string sitename, string url);
}

[Serializable]
public class CommunicationObjArgs : ExternalDataEventArgs
{
    public CommunicationObjArgs(Guid id) : base(id) { }
    public string webID;
}

class StateObject
{
    public SPWeb web;
    public Guid instanceId;
    public StateObject(Guid instanceId, SPWeb web)
    {
        this.instanceId = instanceId;
        this.web = web;
    }
}

class TrainingSiteCreationService : SPWorkflowExternalDataExchangeService, ITrainingSiteCreationService
{
    public event EventHandler<CommunicationObjArgs> MessageIn;

    public void CreateTrainingSite(string sitename, string url)
    {
        ThreadPool.QueueUserWorkItem(delegate(object state)
        {
            StateObject sObject = state as StateObject;
            string webID = string.Empty;
            using (SPSite siteCollection = new SPSite(url))
            {
                using (SPWeb web = siteCollection.OpenWeb())
                {
                    using (SPWeb trainingWeb = web.Webs.Add(sitename))
                    {
                        trainingWeb.Description = "This site is created by a pluggable workflow service.";
                        trainingWeb.Title = sitename;
                        trainingWeb.Update();
                        webID = trainingWeb.ID.ToString();
                    }

                }
            }
            RaiseEvent(sObject.web, sObject.instanceId,
                typeof(ITrainingSiteCreationService),
                "MessageIn", new object[] { webID });
        }, new StateObject(WorkflowEnvironment.WorkflowInstanceId,
            this.CurrentWorkflow.ParentWeb));
    }

    public override void  CallEventHandler(Type eventType, string eventName, object[] eventData, SPWorkflow workflow, string identity, IPendingWork workHandler, object workItem)
    {
        var msg = new CommunicationObjArgs(workflow.InstanceId);
        msg.webID = eventData[0].ToString();
        msg.WorkHandler = workHandler;
        msg.WorkItem = workItem;
        msg.Identity = identity;
        this.MessageIn(null, msg);
    }

    public override void CreateSubscription(MessageEventSubscription subscription)
    {
        throw new NotImplementedException();
    }

    public override void DeleteSubscription(Guid subscriptionId)
    {
        throw new NotImplementedException();
    }
}

}

Answer 1

I was able to find the problem.

On the onworkflow activated Invoking method I was setting another fields,

and no these

callExternalMethodActivitysitename = twInfo.Code;

callExternalMethodActivityurl = workflowProperties.WebUrl;

so, when it gets to the call external method, they were blank, too obvius after looking it very detailed.

Answer 2

I would suggest you to create a custom business object which has these two properties. Further you need to make this object serializable and use this object to communicate with the method in your workflow service.

I did something like this yestarday and it works like a charm when you need to supply multiple parameters to your WF service.