using (SPSite site = new SPSite(url))
                {
                    using (SPWeb oWeb = site.OpenWeb())
                    {
                        var workflowServiceManager = new WorkflowServicesManager(oWeb);
                        var workflowSubscriptionService = workflowServiceManager.GetWorkflowSubscriptionService();

                        //get all workflows associated with the list
                        var subscriptions = workflowSubscriptionService.EnumerateSubscriptionsByList(list.ID);

                        foreach (var workflowSubscription in subscriptions)
                        {

                            var inputParameters = new Dictionary<string, object>();


                            WorkflowInstanceService instanceService = workflowServiceManager.GetWorkflowInstanceService();

                            if (instanceService != null)
                            {
                                foreach (WorkflowInstance wfInstance in instanceService.EnumerateInstancesForListItem(list.ID, currentItem.ID))
                                {
                                    SPWorkflow wf = new SPWorkflow(currentItem, wfInstance.Id);
                                }
                            }
                        }

                        SPWorkflowManager spWorkflowManager = site.WorkflowManager;
                        SPWorkflowFilter filter = new SPWorkflowFilter();

                        filter.InclusiveFilterStates = SPWorkflowState.Running;

                        SPWorkflowTaskCollection workTaskColl = oWeb.Site.WorkflowManager.GetItemTasks(currentItem, filter);

                        foreach (SPWorkflowTask task in workTaskColl)
                        {
                        }

                        foreach (SPWorkflow workflow in spWorkflowManager.GetItemActiveWorkflows(currentItem))
                        {
                            foreach (SPWorkflowTask t in workflow.Tasks)
                            {
                            }
                        }

                        foreach (SPWorkflow instance in spWorkflowManager.GetItemWorkflows(currentItem))
                        {


                        }
                    }
                }

using (SPSite mySite = new SPSite(SPContext.Current.Web.Url))
                        {
                            using (SPWeb myWeb = mySite.OpenWeb())
                            {
                                var filteredtaskItem = (from SPListItem itm in myWeb.Lists.TryGetList("TaskListName").Items
                                                        where GetRelatedItem2(myWeb, itm["Related Items"].ToString() + "") == itemID.ToString()
                                                        select itm).ToList();


                                foreach (SPListItem item in filteredtaskItem)
                                {
                                }
                            }
                        }


public string GetRelatedItem2(SPWeb web, string relatedItems)
        {
            string itemID = string.Empty;
            relatedItems = relatedItems.Trim(new char[] { '[', '{', '}', ']' });
            string[] relatedItemsVals = relatedItems.Split(',');
            Dictionary<string, string> items = new Dictionary<string, string>();
            foreach (var itemsVal in relatedItemsVals)
            {
                string[] keyval = itemsVal.Split(':');
                items[keyval[0].Trim('"')] = keyval[1].Trim('"');
            }

            string itemIDStr = items["ItemId"];
            string listIDStr = items["ListId"];
            Guid listID = new Guid(listIDStr);
            SPList itemList = web.Lists[listID];
            SPItem item = null;
            try
            {
                item = itemList.GetItemById(int.Parse(itemIDStr));
                if (item != null)
                {
                    itemID = item["ID"].ToString();
                }
            }
            catch (Exception ex)
            {

                itemID = string.Empty;
            }
            //SPItem item = itemList.GetItemById(int.Parse(itemIDStr));
            return itemID;
        }