Using CallExternalMethodActivity/HandleExternalEventActivity in StateMachine
- by AngrySpade
I'm attempting to make a StateMachine execute some database action between states.
So I have a "starting" state that uses CallExternalMethodActivity to call a "BeginExecuteNonQuery" function on an class decorated with ExternalDataExchangeAttribute. After that it uses a SetStateActivity to change to an "ending" state.
The "ending" state uses a HandleExternalEventActivity to listen to a "EndExecuteNonQuery" event.
I can step through the local service, into the "BeginExecuteNonQuery" function.
The problem is that the "EndExecuteNonQuery" is null.
public class FailoverWorkflowController : IFailoverWorkflowController
{
private readonly WorkflowRuntime workflowRuntime;
private readonly FailoverWorkflowControlService failoverWorkflowControlService;
private readonly DatabaseControlService databaseControlService;
public FailoverWorkflowController()
{
workflowRuntime = new WorkflowRuntime();
workflowRuntime.WorkflowCompleted += workflowRuntime_WorkflowCompleted;
workflowRuntime.WorkflowTerminated += workflowRuntime_WorkflowTerminated;
ExternalDataExchangeService dataExchangeService = new ExternalDataExchangeService();
workflowRuntime.AddService(dataExchangeService);
databaseControlService = new DatabaseControlService();
workflowRuntime.AddService(databaseControlService);
workflowRuntime.StartRuntime();
}
...
}
...
public void BeginExecuteNonQuery(string command)
{
Guid workflowInstanceID = WorkflowEnvironment.WorkflowInstanceId;
ThreadPool.QueueUserWorkItem(delegate(object state)
{
try
{
int result = ExecuteNonQuery((string)state);
EndExecuteNonQuery(null, new ExecuteNonQueryResultEventArgs(workflowInstanceID, result));
}
catch (Exception exception)
{
EndExecuteNonQuery(null, new ExecuteNonQueryResultEventArgs(workflowInstanceID, exception));
}
}, command);
}
What am I doing wrong with my implementation?
-Stan
