通过递归（自联接表）生成xml文件不会产生所需的层次结构_Xml_Vb.net_Recursion_Xmltextwriter

通过递归（自联接表）生成xml文件不会产生所需的层次结构

xml vb.net recursion

通过递归（自联接表）生成xml文件不会产生所需的层次结构,xml,vb.net,recursion,xmltextwriter,Xml,Vb.net,Recursion,Xmltextwriter,我的任务是从自联接表中填充的数据生成XML文件；所有XML文件必须符合自联接中定义的层次结构我已经编写了一些递归代码来实现这一点，并取得了一些成功，但我的逻辑似乎从未正确显示层次结构；某些父节点始终阻止显示为父节点和子节点（无子节点）例如，我有以下理想的XML结构： <?xml version="1.0" encoding="utf-8"?> <MYREPORT> <HEADER> <HEADER_ID></

我的任务是从自联接表中填充的数据生成XML文件；所有XML文件必须符合自联接中定义的层次结构

我已经编写了一些递归代码来实现这一点，并取得了一些成功，但我的逻辑似乎从未正确显示层次结构；某些父节点始终阻止显示为父节点和子节点（无子节点）

例如，我有以下理想的XML结构：

 <?xml version="1.0" encoding="utf-8"?>  
 <MYREPORT>  
   <HEADER>  
    <HEADER_ID></HEADER_ID>  
    <HEADER_DESC></HEADER_DESC>  
    <HEADER_CODE></HEADER_CODE>  
    <HEADER_NAME></HEADER_NAME>  
    <HEADER_DATE></HEADER_DATE>  
    <HEADER_DATE2></HEADER_DATE2>  
    <AS_AT></AS_AT>  
  </HEADER>  
  <BODY>   
    <ITEMS_INFO>  
      <ITEM_CODE></ITEM_CODE>  
      <ITEM_DESC></ITEM_DESC>  
      <AMOUNT></AMOUNT>  
    </ITEMS_INFO>  
  </BODY>  
</MYREPORT>

但是我继续得到下面的XML输出，

显示为

parentNode

块（这是正确的），也显示为

childNode

——没有后代（这是错误的）

谢谢

ElementId   ElementName         ParentId    ElementLevel 
1           MYREPORT            NULL            0  
2       HEADER              1           1  
3       HEADER_ID           2           2  
4       HEADER_DESC         2           2  
5       HEADER_CODE         2           2  
6       HEADER_NAME         2           2  
7       HEADER_DATE         2           2  
8       HEADER _DATE2           2           2  
9       AS_AT               2           2  
10      BODY                1           1  
12      ITEMS_INFO          10          2  
13      ITEM_CODE           12          3  
14      ITEM_DESC           12          3  
15      AMOUNT              12          3

<?xml version="1.0" encoding="utf-8"?>
<MYREPORT>
  <HEADER>
    <HEADER_ID>8:564</HEADER_ID>
    <HEADER_DESC>9:564</HEADER_DESC>
    <HEADER_CODE>10:564</HEADER_CODE>
    <HEADER_NAME>11:564</HEADER_NAME>
    <HEADER_DATE>12:564</HEADER_DATE>
    <HEADER_DATE2>13:564</HEADER_DATE2>
    <AS_AT>14:564</AS_AT>
 </HEADER>
 <BODY>
    <ITEMS_INFO>
      <ITEM_CODE>17:737</ITEM_CODE>
      <ITEM_DESC>18:737</ITEM_DESC>
      <AMOUNT>19:737</AMOUNT>
    </ITEMS_INFO>
    <ITEMS_INFO>20:737</ITEMS_INFO>
  </BODY>
</MYREPORT>

Private xmlWriter As New XmlTextWriter(My.Settings.xmlPath & "Rep.xml", System.Text.Encoding.UTF8)
Sub Main()

    Try
        Dim ds As DataSet = SqlHelper.ExecuteDataset(My.Settings.SqlUserRoleServices, CommandType.StoredProcedure, "getTest")
        ds.Tables(1).Columns.Add("isParsed", GetType(System.Int16))
        ds.Tables(1).AcceptChanges()
        Dim dr As DataRelation = New DataRelation("ElementSelf", ds.Tables(1).Columns("ElementId"), ds.Tables(1).Columns("ParentId"), True)
        ds.Relations.Add(dr)

        xmlWriter.Formatting = Formatting.Indented
        For Each StartRow As DataRow In ds.Tables(0).Rows
            If StartRow.IsNull("ParentId") Then
                xmlWriter.WriteStartDocument()
                xmlWriter.WriteStartElement(StartRow("ElementName"))
            End If
        Next

        For Each parentRow As DataRow In ds.Tables(1).Rows
            If (Not parentRow.IsNull("ParentId")) And parentRow.IsNull("IsParsed") Then
                parentRow("IsParsed") = 1
                doRecursion(parentRow, dr, xmlWriter)
                parentRow.AcceptChanges()
            End If
        Next

        xmlWriter.WriteEndElement()
        xmlWriter.WriteEndDocument()
        xmlWriter.Flush()
        xmlWriter.Close()
    Catch ex As Exception
        Console.WriteLine(ex.Message)
        Console.ReadKey()
    End Try
End Sub

Private Sub doRecursion(ByRef parentRow As DataRow, ByRef dr As DataRelation, ByRef xmlwriter As XmlTextWriter)
    Dim children As DataRow() = parentRow.GetChildRows(dr)

    If children.Any Then
        xmlwriter.WriteStartElement(parentRow("ElementName").ToString)

        For Each brow As DataRow In children
            If brow("IsParsed") Is DBNull.Value Then
                brow("IsParsed") = 1
                brow.AcceptChanges()
                doRecursion(brow, dr, xmlwriter)
                xmlwriter.WriteElementString(brow("ElementName"), Date.Now.Second & ":" & Date.Now.Millisecond)
                System.Threading.Thread.Sleep(1000)
                brow.AcceptChanges()
                parentRow.AcceptChanges()
            Else
                Exit For
            End If
        Next
        xmlwriter.WriteEndElement()
    Else
        Return
    End If
End Sub