ASP.net 2005 Treeview 無限分類非地遞迴終極解決方案

asp.net|treeview|遞迴|解決

為了速度緩衝DataTable

        Public Function GetTreeTable() As DataTable

                Dim dt As New DataTable()

                dt = HttpContext.Current.Cache("Treeview")

                If dt Is Nothing Then

                    Dim Conn As New SqlConnection

                    Dim clsConnDatabase As New ConnectionDatabase

                    Conn = clsConnDatabase.ConnDatabase

 

                    Dim Command As New SqlCommand

                    Command.Connection = Conn

                    Command.CommandText = "GetTreeview"

                    Command.CommandType = CommandType.StoredProcedure

                    Command.ExecuteNonQuery()

 

                    Dim da As New SqlDataAdapter(Command)

                    dt = New DataTable()

                    da.Fill(dt)

                    HttpContext.Current.Cache.Insert("Treeview", dt)

                End If

                Return dt

            End Function

 

這裡是主要阿

Public Sub PopulateNodes(ByVal nodes As TreeNodeCollection, Optional ByVal intParentID As Int32 = 0)

                Dim dt As New DataTable()

                dt = clsWebForms.GetTreeTable()

                Dim strExpression As String

strExpression = "[parentID] = " & intParentID

                Dim foundRows() As DataRow

                foundRows = dt.Select(strExpression)

 

                Dim I As Integer

                For I = 0 To foundRows.GetUpperBound(0)

                    Dim tn As New TreeNode()

                    tn.Text = foundRows(I).Item(“TableName”).ToString()

                    tn.Value = foundRows(I).Item("ID").ToString()

                    Dim dr() As DataRow

                    dr = dt.Select("[parentID] = " & tn.Value)

                    If dr.GetUpperBound(0) > -1 Then

                        tn.PopulateOnDemand = True

                    End If

                    nodes.Add(tn)

                Next

            End Sub

 

建立WebForm 放入Treeview

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

        If Not Page.IsPostBack Then   

PopulateNodes(TreeView1.Nodes, 0)

        End If

    End Sub

 

    Protected Sub TreeView1_TreeNodePopulate(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.TreeNodeEventArgs) Handles TreeView1.TreeNodePopulate

                PopulateNodes(e.Node.ChildNodes, e.Node.Value)

    End Sub

至於速度我沒測試，如果大家有興趣幫忙測測。

 

題外話（突然發現自己老了，26歲了寫了快7年的程式了 一直使用VB各種版本, 及  Masm（MS宏組合語言）在VB 6.0 時代 2000 年左右建立了 以VB 編程為主的個人首頁編程浪子） by Shadow

註：本文轉自http://blog.csdn.net/shadowsky/archive/2006/06/18/811461.aspx

這幾天在寫HRM的時候 這問題搞了我兩天，哈哈！開始在使用Google 找了半天都是一堆垃圾，都是使用演算法的較多， 後來就去了www.asp.net 找到點啟示。好了廢話多說無用。首先表結構如下 表名 Test寫個預存程序 GetTreeview這個不用我說了吧下面用到