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);             }         }