如何在C＃中递归调用for循环中的函数 [英] How To Recursively Call a Function Inside for Loop in C#

问题描述

我想使用for循环调用递归函数，但是当它以递归方式调用它从开始值开始时，我想逐个传递所有值，但是我的代码在下面传递了一个（相同）值时间..那么如何将所有值传递给函数调用？

  protected   String  BottomTree（ String  AncestorFamilyID，ArrayList RelationPath）
 {
 ArrayList bottomMembers =  new  ArrayList（）; 
 
 sSQL =   SELECT DISTINCT AF_MemberID FROM Family_Master; 
 sSQL = sSQL +   WHERE AF_FamilyID IN（ + AncestorFamilyID +  ）; 
 
 DS2 =  new  DataSet（）; 
 da2 =  new  OdbcDataAdapter（sSQL，conn）; 
 da2.Fill（DS2）; 
 
  if （DS2.Tables.Count >   0 ）
 {
  if （DS2.Tables [   table]。Rows.Count >   0 ）
 {
  for （ int  i =  0 ; i <  DS2.Tables [  table]。Rows.Count; i ++）
 {
 bottomMembers.Add（DS2.Tables [  table]。行[i] [  AF_MemberID]的ToString（））; 
 
  if （bottomMembers [i] .ToString（）== lblUserToMemberID.Text）
 {
  return  lblUserToMemberID.Text; 
} 
  else  
 {
 sSQL =   SELECT AF_FamilyID FROM Family_Master; 
 sSQL = sSQL +   WHERE AF_MemberID =' + bottomMembers [i] +  '; 
 sSQL = sSQL +   AND AF_MemberType IN（'H'）; 
 
 DS3 =  new  DataSet（）; 
 da3 =  new  OdbcDataAdapter（sSQL，conn）; 
 da3.Fill（DS3）; 
 
  if （DS3.Tables.Count >   0 ）
 {
  if （DS3.Tables [   table]。Rows.Count >   0 ）
 {
 lblUserFromFamilyID.Text = DS3.Tables [ 表]。行[ 0 ] [  AF_FamilyID]的ToString（）; 
} 
} 
 
  return  BottomTree（lblUserFromFamilyID.Text，RelationPath）; 
} 
} 
} 
} 
 DS2.Dispose（）; 
 da2.Dispose（）; 
 
 
  return   null ; 
 
} 

任何帮助？

解决方案

您必须使用2种方法。首先将调用第二个，只有第二个将是递归的！

以下是使用实体框架的示例：

 public static int [] GetCategoyWithChildrenIDList（SLOnlineShopEntities dataContext，int categoryID）
 {
 List <   Category  >  childrenTree = GetCategoryWithChildrenTreeAsList（dataContext，categoryID）; 
 if（childrenTree.Count <     1 ）  
                   return     new     int [0];   
           //   
          列表< int  >  idList = new List <   int  > （）; 
 // 
 foreach（childrenTree中的类别类别）
 {
 idList.Add（category.ID）; 
} 
 // 
返回idList.ToArray（）; 
} 
 
私有静态列表<  类别 >  GetCategoryWithChildrenTreeAsList（SLOnlineShopEntities dataContext，int categoryID）
 {
 List <  类别 >  childrenTree =新列表<  类别 > （）; 
类别mainCategory = dataContext.Categories.FirstOrDefault（c => c.ID == categoryID&&（c.Inactive == false || c.Inactive == null））; 
 if（mainCategory == null）
 return childrenTree; 
 // 
 childrenTree.Add（mainCategory）; 
列表<  类别 >  directChildrenList = dataContext.Categories.Where（c => c.ParentID == categoryID&&（c.Inactive == false || c.Inactive == null））。ToList（）; 
 if（directChildrenList.Count == 0）
 return childrenTree; 
 // 
 childrenTree.AddRange（directChildrenList）; 
 // 
 foreach（directChildrenList中的类别类别）
 {
 List <  类别 >  tempList = GetCategoryWithChildrenTreeAsList（dataContext，category.ID）; 
 if（tempList.Count> 0）
 childrenTree.AddRange（tempList）; 
} 
 // 
返回childrenTree; 
} 
 

我想，你正在寻找这个



使用公用表表达式的递归查询

Hi,I want to call a recursive function using for loop,but when it calls recursively its start from beginning value , I want to pass the all values one by one ,but my code below passes the one(same) value every time..So how can i pass the all values to the function call?

protected String BottomTree(String AncestorFamilyID, ArrayList RelationPath)
    {
        ArrayList bottomMembers = new ArrayList();

        sSQL = "SELECT DISTINCT AF_MemberID FROM Family_Master";
        sSQL = sSQL + " WHERE AF_FamilyID IN(" + AncestorFamilyID + ")";

        DS2 = new DataSet();
        da2 = new OdbcDataAdapter(sSQL, conn);
        da2.Fill(DS2);

        if (DS2.Tables.Count > 0)
        {
            if (DS2.Tables["table"].Rows.Count > 0)
            {
                for (int i = 0; i < DS2.Tables["table"].Rows.Count; i++)
                {
                    bottomMembers.Add(DS2.Tables["table"].Rows[i]["AF_MemberID"].ToString());

                    if (bottomMembers[i].ToString() == lblUserToMemberID.Text)
                    {
                        return lblUserToMemberID.Text;
                    }
                    else
                    {
                        sSQL = "SELECT AF_FamilyID FROM Family_Master";
                        sSQL = sSQL + " WHERE AF_MemberID = '" + bottomMembers[i] + "'";
                        sSQL = sSQL + " AND AF_MemberType IN('H')";

                        DS3 = new DataSet();
                        da3 = new OdbcDataAdapter(sSQL, conn);
                        da3.Fill(DS3);

                        if (DS3.Tables.Count > 0)
                        {
                            if (DS3.Tables["table"].Rows.Count > 0)
                            {
                                lblUserFromFamilyID.Text = DS3.Tables["table"].Rows[0]["AF_FamilyID"].ToString();
                            }
                        }

                        return BottomTree(lblUserFromFamilyID.Text, RelationPath);
                    }
                }
            }
        }
        DS2.Dispose();
        da2.Dispose();


        return null;

    }

Any Help?

解决方案

You have to use 2 methods. First will invoke the second one and only the second will be recursive!
Here is an example by using Entity Framework:

public static int[] GetCategoyWithChildrenIDList(SLOnlineShopEntities dataContext, int categoryID)
{
    List<Category> childrenTree = GetCategoryWithChildrenTreeAsList(dataContext, categoryID);
    if (childrenTree.Count < 1)
        return new int[0];
    //
    List<int> idList = new List<int>();
    //
    foreach (Category category in childrenTree)
    {
        idList.Add(category.ID);
    }
    //
    return idList.ToArray();
}

private static List<Category> GetCategoryWithChildrenTreeAsList(SLOnlineShopEntities dataContext, int categoryID)
{
    List<Category> childrenTree = new List<Category>();
    Category mainCategory = dataContext.Categories.FirstOrDefault(c => c.ID == categoryID && (c.Inactive == false || c.Inactive == null));
    if (mainCategory == null)
        return childrenTree;
    //
    childrenTree.Add(mainCategory);
    List<Category> directChildrenList = dataContext.Categories.Where(c => c.ParentID == categoryID && (c.Inactive == false || c.Inactive == null)).ToList();
    if (directChildrenList.Count == 0)
        return childrenTree;
    //
    childrenTree.AddRange(directChildrenList);
    //
    foreach (Category category in directChildrenList)
    {
        List<Category> tempList = GetCategoryWithChildrenTreeAsList(dataContext, category.ID);
        if (tempList.Count > 0)
            childrenTree.AddRange(tempList);
    }
    //
    return childrenTree;
}

i think ,you are looking for this

Recursive queries using Common table expression

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