這幾天在寫HRM的時候 這問題搞了我兩天，開始在使用Google 找了半天都是一堆垃圾，都是使用算法的較多， 後來就去了的msdn.yesky.com 找到點啟示。 好了廢話多說無用。
首先表結構如下 表名 Test
寫個存儲過程 GetTreeview
這個不用我說了吧下面用到
為了速度緩存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。
