topcat 姍舞之間的極度凝聚

Imports System.Data 
Imports System.Data.SqlClient 

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    '*****取得Tree物件*****
    '利用Session 當Tree已經建立過，不重新建立，直接從Session中取得，加快速度
    If Session("Tree1") Is Nothing Then
        'Tree不曾建立過→呼叫建立TreeView程序
        Call InitTree() '初始化Tree
        Call BuildTree()    '建立Tree內容
    End If
    '宣告Tree物件
    Dim Tree1 As TreeView
    '從Session中取得Tree物件
    Tree1 = Session("Tree1")

    '設定Tree的ImageSet
    Tree1.ImageSet = TreeViewImageSet.XPFileExplorer
    '置放於PlaceHolder
    Me.PlaceHolder1.Controls.Add(Tree1)
End Sub

Sub InitTree()
    '********初始化Tree********

    '定義TreeView物件並實體化
    Dim Tree1 As New TreeView
    '定義一個TreeNode並實體化
    Dim tmpNote As New TreeNode
    '設定【根目錄】相關屬性內容
    tmpNote.Text = "首頁"
    tmpNote.Value = "0"
    tmpNote.NavigateUrl = "PtestTreeView3.aspx"
    tmpNote.Target = "_Top"

    'Tree建立該Node
    Tree1.Nodes.Add(tmpNote)

    '將Tree存放入Session中
    Session("Tree1") = Tree1

End Sub

Sub BuildTree()
    '********建立樹狀結構********

    '宣告TreeView
    Dim Tree1 As TreeView

    '如果Session中沒有Tree,初始化Tree
    If Session("Tree1") Is Nothing Then
        Call InitTree()
    End If
    Tree1 = Session("Tree1")

    '取得根目錄節點
    Dim RootNode As TreeNode
    RootNode = Tree1.Nodes(0)
    Dim rc As String

    '呼叫建立子節點的函數
    rc = AddNodes(RootNode, 0)
    Session("Tree1") = Tree1

End Sub

Sub GetDataTable()
    '取得DataTable

    '宣告相關變數
    Dim ConnStr As String
    Dim Conn As SqlConnection
    Dim Da As SqlDataAdapter
    Dim Ds As DataSet
    Dim dt As DataTable
    Dim SqlTxt As String

    Try
        '設定連接字串，請修改符合您的資料來源的ConnectionString
        ConnStr = "Data Source=Local\SQLEXPRESS;Persist Security Info=True;User ID=sa;Password=xxxxxxxxxxx;Initial Catalog=DTest"
        '建立Connection
        Conn = New SqlConnection(ConnStr)
        Conn.Open()

        '設定資料來源T-SQL
        SqlTxt = "SELECT * FROM TTestTree"    '請修改您的資料表名稱
        '實體化DataAdapter並且取得資料
        Da = New SqlDataAdapter(SqlTxt, Conn)
        '實體化DataSet
        Ds = New DataSet
        '資料填入DataSet
        Da.Fill(Ds)
        '設定DataTable
        dt = New DataTable
        dt = Ds.Tables(0)
        '將DataTable放入Session中
        Session("Dt") = dt
        '關閉連線
        Conn.Close()

    Catch ex As Exception
        Me.lblMessage.Text = ex.Message
    Finally

        '資源回收
        Ds = Nothing
        Da = Nothing
        Conn = Nothing

    End Try

End Sub

Function AddNodes(ByRef tNode As TreeNode, ByVal PId As Integer) As String
    '******** 遞迴增加樹結構節點 ********
    Try
        '如果Session中沒有DataTable→取得DataTable
        If Session("dt") Is Nothing Then
            Call GetDataTable()
        End If
        '定義DataTable
        Dim Dt As DataTable
        '從Session中取得DataTable
        Dt = Session("Dt")

        '定義DataRow承接DataTable篩選的結果
        Dim rows() As DataRow
        '定義篩選的條件
        Dim filterExpr As String
        filterExpr = "ParentId = " & PId
        '資料篩選並把結果傳入Rows
        rows = Dt.Select(filterExpr)

        '如果篩選結果有資料
        If rows.GetUpperBound(0) >= 0 Then


            Dim row As DataRow
            Dim tmpNodeId As Long
            Dim tmpsText As String
            Dim tmpsValue As String
            Dim tmpsUrl As String
            Dim tmpsTarget As String
            Dim NewNode As TreeNode
            Dim rc As String

            '逐筆取出篩選後資料
            For Each row In rows
                '放入相關變數中
                tmpNodeId = row(0)
                tmpsText = row(2)
                tmpsValue = row(3)
                tmpsUrl = row(4)
                tmpsTarget = row(5)

                '實體化新節點
                NewNode = New TreeNode
                '設定節點各屬性
                NewNode.Text = tmpsText
                NewNode.Value = tmpsValue
                NewNode.NavigateUrl = tmpsUrl
                NewNode.Target = tmpsTarget
                '將節點加入Tree中
                tNode.ChildNodes.Add(NewNode)

                '呼叫遞回取得子節點
                rc = AddNodes(NewNode, tmpNodeId)

            Next
        End If
        '傳回成功訊息
        AddNodes = "Success"

    Catch ex As Exception
        Me.lblMessage.Text = ex.Message
        AddNodes = "False"

    End Try
End Function