Suspension et reprise d'un workflow

Les workflows seront suspendus et reprendront en réponse à des signets et des activités bloquantes, telles que Delay, mais vous pouvez aussi suspendre, décharger et reprendre explicitement un workflow à l'aide de la persistance.

Suspension d'un workflow

Pour suspendre un workflow, utilisez Unload. Cette méthode demande que le workflow soit persistant et déchargé, et lève une exception TimeoutException si le workflow n'est pas déchargé en trente secondes.

try  
{  
    // attempt to unload will fail if the workflow is idle within a NoPersistZone  
    application.Unload(TimeSpan.FromSeconds(5));  
}  
catch (TimeoutException e)  
{  
    Console.WriteLine(e.Message);  
}  

Reprise d'un workflow

Pour reprendre la progression d'un workflow qui était déjà suspendu et déchargé, utilisez Load. Cette méthode charge un workflow d'un magasin de persistances dans la mémoire.

WorkflowApplication application = new WorkflowApplication(activity);  
application.InstanceStore = instanceStore;  
application.Load(id);  

Exemple

L'exemple de code suivant montre comment suspendre et reprendre un workflow à l'aide de la persistance.

static string bkName = "bkName";  
static void Main(string[] args)
{  
    StartAndUnloadInstance();  
}  
  
static void StartAndUnloadInstance()
{  
    AutoResetEvent waitHandler = new AutoResetEvent(false);  
    WorkflowApplication wfApp = new WorkflowApplication(GetDelayedWF());  
    SqlWorkflowInstanceStore instanceStore = SetupSqlpersistenceStore();  
    wfApp.InstanceStore = instanceStore;  
    wfApp.Extensions.Add(SetupMyFileTrackingParticipant);  
    wfApp.PersistableIdle = (e) => {          ///persists application state and remove it from memory
    return PersistableIdleAction.Unload;  
    };  
    wfApp.Unloaded = (e) => {  
        waitHandler.Set();  
    };  
    Guid id = wfApp.Id;  
    wfApp.Run();  
    waitHandler.WaitOne();  
    LoadAndCompleteInstance(id);  
}  
  
static void LoadAndCompleteInstance(Guid id)
{
    Console.WriteLine("Press <enter> to load the persisted workflow");  
    Console.ReadLine();  
    AutoResetEvent waitHandler = new AutoResetEvent(false);  
    WorkflowApplication wfApp = new WorkflowApplication(GetDelayedWF());  
    wfApp.InstanceStore =  
        new SqlWorkflowInstanceStore(ConfigurationManager.AppSettings["SqlWF4PersistenceConnectionString"].ToString());  
    wfApp.Completed = (workflowApplicationCompletedEventArgs) => {  
        Console.WriteLine("\nWorkflowApplication has Completed in the {0} state.",  
            workflowApplicationCompletedEventArgs.CompletionState);  
    };  
    wfApp.Unloaded = (workflowApplicationEventArgs) => {  
        Console.WriteLine("WorkflowApplication has Unloaded\n");  
        waitHandler.Set();  
    };  
    wfApp.Load(id);  
    wfApp.Run();  
    waitHandler.WaitOne();  
}  
  
public static Activity GetDelayedWF()
{  
    return new Sequence {  
        Activities ={  
            new WriteLine{Text="Workflow Started"},  
            new Delay{Duration=TimeSpan.FromSeconds(10)},  
            new WriteLine{Text="Workflow Ended"}  
        }  
    };  
}  
  
private static SqlWorkflowInstanceStore SetupSqlpersistenceStore()
{
     string connectionString = ConfigurationManager.AppSettings["SqlWF4PersistenceConnectionString"].ToString();  
    SqlWorkflowInstanceStore sqlWFInstanceStore = new SqlWorkflowInstanceStore(connectionString);  
    sqlWFInstanceStore.InstanceCompletionAction = InstanceCompletionAction.DeleteAll;  
    InstanceHandle handle = sqlWFInstanceStore.CreateInstanceHandle();  
    InstanceView view = sqlWFInstanceStore.Execute(handle, new CreateWorkflowOwnerCommand(), TimeSpan.FromSeconds(5));  
    handle.Free();  
    sqlWFInstanceStore.DefaultInstanceOwner = view.InstanceOwner;  
    return sqlWFInstanceStore;  
}