اکتیویتی های مرکب در Workflow

using System.Activities;
using System.Collections.ObjectModel;
namespace ActivityLibrary
{
    public class MySequence : NativeActivity
    {
        public Collection Activities { get; set; }
        public MySequence()
        {
            Activities = new Collection();
        }
        int activityCounter = 0;
        protected override void CacheMetadata(NativeActivityMetadata metadata)
        {
            foreach (var activity in Activities)
            {
                metadata.AddImplementationChild(activity);
            }
        }
        protected override void Execute(NativeActivityContext context)
        {
            ScheduleActivities(context);
        }
        void ScheduleActivities(NativeActivityContext context)
        {
            if (activityCounter < Activities.Count)
                context.ScheduleActivity(this.Activities[activityCounter++], OnActivityCompleted);
        }
        void OnActivityCompleted(NativeActivityContext context, ActivityInstance completedInstance)
        {
            ScheduleActivities(context);
        }
    }
}

        static Activity GetTestMySquenceWF()
        {
            return new ActivityLibrary.MySequence()
            {
                Activities ={
                    new WriteLine(){Text="WriteLine1"},
                    new WriteLine(){Text="WriteLine2"},
                    new WriteLine(){Text="WriteLine3"}
                }
            };
        }

WorkflowInvoker.Invoke(GetTestMySquenceWF());

        protected override void CacheMetadata(NativeActivityMetadata metadata)
        {
            foreach (var activity in Activities)
            {
                metadata.AddImplementationChild(activity);
            }
        }

void ScheduleActivities(NativeActivityContext context)
        {
            //if (activityCounter < Activities.Count)
                //context.ScheduleActivity(this.Activities[activityCounter++], OnActivityCompleted);
            for (int i = 0; i < Activities.Count; i++)
            {
                context.ScheduleActivity(this.Activities[i]);
            }
        }