递归在算法在工作流程引擎中的应用

递归在算法在工作流程引擎中的应用

递归做为一种算法在程序设计语言中广泛应用.是指函数/过程/子程序在运行过程中直接或间接调用自身而产生的重入现象.递归是计算机科学的一个重要概念,递归的方法是程序设计中有效的方法,采用递归编写程序能使程序变得简洁和清晰.。

递归在工作流程引擎中有广泛的应用，以以下事例来说明：

应用一：退回到指定的节点，要把当前节电与退回节点之间的节点数据清空。

/// <summary>

        /// 递ÌY归¨¦删¦?除y两¢?个?节¨²点Ì?之?间?的Ì?数ºy据Y

        /// </summary>

        /// <param name="nds">到Ì?达ä?的Ì?节¨²点Ì?集¡¥合?</param>

        publicvoid DeleteToNodesData(Nodes nds)

        {

            /*开a始º?遍À¨¦历¤¨²到Ì?达ä?的Ì?节¨²点Ì?集¡¥合?*/

            foreach (Node nd in nds)

            {

                Work wk = nd.HisWork;

                wk.OID = this.WorkID;

                if (wk.Delete() == 0)

                {

                    wk.FID = this.WorkID;

                    if (wk.Delete(WorkAttr.FID, this.WorkID) == 0)

                        continue;

                }

 

                /*说¦Ì明¡Â:已°?经-删¦?除y该?节¨²点Ì?数ºy据Y。¡ê*/

                DBAccess.RunSQL("DELETE WF_GenerWorkerList WHERE (WorkID=" + this.WorkID + " OR FID=" + this.WorkID + ") AND FK_Node=" + nd.NodeID);

 

                //删¦?除y正y常¡ê的Ì?垃¤?圾?数ºy据Y。¡ê

                DBAccess.RunSQL("DELETE WF_GenerWorkFlow WHERE WorkID NOT IN (SELECT WorkID FROM WF_GenerWorkerList )");

                DBAccess.RunSQL("DELETE WF_GenerFH WHERE FID NOT IN (SELECT FID FROM WF_GenerWorkerList)");

 

                

                DeleteToNodesData(nd.HisToNodes);

            }

        }

 

 

 

应用二：在分合流程过程中，流程结束时，要根据用户的需要判断并杀掉没有完成的进程。

 

/// <summary>

        /// 结¨¢束º?流¢¡Â程¨¬

        /// </summary>

        /// <returns></returns>

        publicstring DoFlowOver()

        {

            // 建¡§立¢¡é流¢¡Â程¨¬事º?例¤y。¡ê

            GenerWorkFlow gwf = newGenerWorkFlow(this.WorkID);

            Node nd = newNode(gwf.FK_Node);

            string msg = this.BeforeFlowOver();

 

            //先¨¨让¨?它¨¹的Ì?子Á¨®流¢¡Â程¨¬结¨¢束º?。¡ê

            WorkerLists wls = newWorkerLists();

            wls.Retrieve(WorkerListAttr.FID, this.WorkID);

            foreach (WorkerList wl in wls)

            {

                WorkFlow wf = newWorkFlow(wl.FK_Flow, wl.WorkID);

                wf.DoFlowOver();

            }

    。。。。。。。。。。。。。。

   ｝

 

 

 

应用三:根据当前节点的ID,向上追溯一个分流节点。

/// <summary>

        /// 获?取¨?它¨¹的Ì?上¦?一°?步?的Ì?分¤?流¢¡Â点Ì?

        /// </summary>

        privateNode _GetHisPriFLNode(Nodes nds)

        {

            foreach (Node mynd in nds)

            {

                if (mynd.IsHL)

                    return mynd;

                else

                    return _GetHisPriFLNode(mynd.HisFromNodes);

            }

            returnnull;

        }

        /// <summary>

        /// 它¨¹的Ì?上¦?一°?步?分¤?流¢¡Â节¨²点Ì?

        /// </summary>

        publicNode HisPriFLNode

        {

            get

            {

                return _GetHisPriFLNode(this.HisFromNodes);

            }

        }