ASP.NET 2005 Treeview终极解决方案

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
　　这里是主要阿
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