Question

我有以下问题：我必须按层次结构对记录集的数据进行排序。

这是来自数据库的数据。

您会看到有两列，即POS和PARENT。这些值必须彼此相关。如果PARENT为0，则新排序中的值仅获得一个连续数字。在这种情况下1-3。

其他值均基于父级获得新的连续数字。

我很确定我可以用C＃解决此问题，但是在这种情况下，VB6是必需的。不幸的是，我在解决VB6问题时遇到了极端问题。

Answer 1

这看起来像一个链表练习。您可以创建一个具有FirstChild对象和NextItem对象的clsListItem类：

Public Position As Integer
Public Hierarchy As String
Public FirstChild As clsListItem
Public NextItem As clsListItem

当您进入列表时，将创建一个新对象并寻找其父对象。然后，您检查父级的FirstChild是否存在。如果不是，则将对象设置为FirstChild，否则使用NextItem浏览子对象，直到NextItem为Nothing。然后，将对象设置为NextItem：

Public Sub Sort(ByVal p_sList As String)
    Dim arrLines
    Dim arrFields
    Dim iCounter As Integer
    Dim objItem As clsListItem
    Dim objParent As clsListItem
    Dim objChild As clsListItem
    Dim iPosition As Integer
    Dim iParent As Integer
    Dim iParentIndex As Integer
    Dim iChildIndex As Integer

    ' Split values into lines
    arrLines = Split(p_sList, vbCrLf)

    ' Initialize Parent Index
    iParentIndex = 1

    For iCounter = 1 To UBound(arrLines) + 1

        arrFields = Split(arrLines(iCounter - 1), ",")

        iPosition = arrFields(0)
        iParent = arrFields(1)

        ' Get Item
        Set objItem = GetItem(iPosition)

        If iParent = 0 Then

            ' This is a top-level item
            objItem.Hierarchy = iParentIndex
            iParentIndex = iParentIndex + 1

        Else

            ' Get Parent
            Set objParent = GetItem(iParent)

            ' Initialize Child Index
            iChildIndex = 1

            If objParent.FirstChild Is Nothing Then
                ' We are the first child
                Set objParent.FirstChild = objItem
            Else

                ' Find last child
                Set objChild = objParent.FirstChild
                iChildIndex = iChildIndex + 1

                Do While Not objChild.NextItem Is Nothing
                    Set objChild = objChild.NextItem
                    iChildIndex = iChildIndex + 1
                Loop

                Set objChild.NextItem = objItem

            End If

            objItem.Hierarchy = objParent.Hierarchy & "." & iChildIndex

        End If

    Next

    Dim sMessage As String

    For iCounter = 1 To colListItems.Count
        Set objItem = colListItems.item(iCounter)
        With objItem
            sMessage = sMessage & .Position & ": " & .Hierarchy & vbCrLf
        End With
    Next

    MsgBox sMessage

End Sub

这应该将所有数据组织到具有所需层次结构的对象中。

获取/创建项目的助手功能：

Public Function GetItem(ByVal p_iPosition As Integer) As clsListItem
    Dim objItem As clsListItem

    On Error GoTo ItemNotFound

    Set objItem = colListItems.item("P" & p_iPosition)

    GoTo ReturnItem

ItemNotFound:

    Set objItem = New clsListItem
    objItem.Position = p_iPosition

    colListItems.Add objItem, "P" & p_iPosition

ReturnItem:
    Set GetItem = objItem
End Function

最后，我用来创建值表的代码（仔细检查，可能是拼写错误）：

Private Function AddPair(ByVal p_sList As String, ByVal p_iPos As Integer, ByVal p_iParent As Integer) As String
    Dim sReturn As String

    sReturn = p_sList

    If sReturn <> "" Then sReturn = sReturn & vbCrLf

    sReturn = sReturn & p_iPos & "," & p_iParent

    AddPair = sReturn


End Function

这是主要的子程序：

Private Sub Form_Load()
    Dim list As String

    list = AddPair(list, 1, 0)
    list = AddPair(list, 13, 0)
    list = AddPair(list, 16, 0)
    list = AddPair(list, 2, 1)
    list = AddPair(list, 12, 1)
    list = AddPair(list, 3, 2)
    list = AddPair(list, 4, 2)
    list = AddPair(list, 5, 2)
    list = AddPair(list, 6, 2)
    list = AddPair(list, 7, 2)
    list = AddPair(list, 8, 7)
    list = AddPair(list, 11, 7)
    list = AddPair(list, 9, 8)
    list = AddPair(list, 10, 8)
    list = AddPair(list, 14, 13)
    list = AddPair(list, 15, 13)
    list = AddPair(list, 17, 16)
    list = AddPair(list, 18, 16)

    Sort (list)

End Sub

从记录集创建层次结构

1 个答案: