燃燒吧~~~TreeView-配合物件導向的設計方式 VB.NET&C# 混合

2008-08-05 置頂文章

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ADO.NET
2008-08-06

在之前的文章-->ASP.NET 2.0動態產生TreeView樹狀結構-C# & VB.NET 混合提到過動態產生Menu

如果和物件導向結合會是什麼樣的情景呢!?(當然顯示出來的結果要是一樣，只是內部設計不同)

有關於物件導向設計方式請參考 -->燃燒吧~~ObjectDataSouce配合物件導向的設計方式連結資料 VB.NET

廢話不多說~實際操作看看吧！

在之前的文章-->ASP.NET 2.0動態產生TreeView樹狀結構-C# & VB.NET 混合提到過動態產生Menu

如果和物件導向結合會是什麼樣的情景呢!?(當然顯示出來的結果要是一樣，只是內部設計不同)

有關於物件導向設計方式請參考 -->燃燒吧~~ObjectDataSouce配合物件導向的設計方式連結資料 VB.NET

廢話不多說~實際操作看看吧！

首先設計一個 objMenu的模型出來

01 ''' <summary>
02 ''' Menu 資料庫物件，資料存取層物件。 By Phoehix - 2008
03 ''' </summary>
04 ''' <remarks></remarks>
05

Public Class objMenu
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Inherits objADU
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Private _ID As Integer
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Private _ParentID As Integer
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Private _Value As String
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Private _Order As Integer
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Public Property MenuID() As Integer
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Get
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Return _ID
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End Get
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Set(ByVal value As Integer)
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_ID = value
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End Set
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End Property
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Public Property MenuParentID() As Integer
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Get
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Return _ParentID
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End Get
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Set(ByVal value As Integer)
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_ParentID = value
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End Set
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End Property
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Public Property MenuValue() As String
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Get
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Return _Value
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End Get
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Set(ByVal value As String)
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_Value = value
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End Set
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End Property
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Public Property MenuOrder() As Integer
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Get
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Return _Order
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End Get
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Set(ByVal value As Integer)
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_Order = value
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End Set
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End Property
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Public Sub New()
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End Sub
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Public Sub New(ByRef row As DataRow)
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GetMenu(row)
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End Sub
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Private Sub GetMenu(ByRef row As DataRow)
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Try
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_ID = Integer.Parse(row(0).ToString())
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_ParentID = Integer.Parse(row(1).ToString())
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_Value = row(2).ToString()
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_Order = Integer.Parse(row(3).ToString())
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Catch ex As Exception
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Throw
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End Try
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End Sub
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Public Overloads Sub Add()
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Try
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Dim SqlTxt As String = "INSERT INTO [Menu] ([ParentID], [Value], [Order]) VALUES (@ParentID, @Value, @Order)"
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Dim Parameters(3) As SqlParameter
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Parameters(0) = New SqlParameter("@ParentID", _ParentID)
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Parameters(1) = New SqlParameter("@Value", _Value)
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Parameters(3) = New SqlParameter("@Order", _Order)
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add(SqlTxt, Parameters)
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Catch ex As Exception
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Throw
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End Try
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End Sub
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Public Overloads Sub Del()
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Try
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Dim SqlTxt As String = "Delete [Menu] WHERE ([ID] = @Original_ID)"
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Dim Parameter As SqlParameter = New SqlParameter("@Original_ID", _ID)
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Del(SqlTxt, Parameter)
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Catch ex As Exception
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Throw
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End Try
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End Sub
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Public Overloads Sub Update()
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Try
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Dim SqlTxt As String = "UPDATE Menu Set ParentID = @ParentID, Value = @Value, Order = @Order WHERE ID = @Original_ID"
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Dim Parameters(4) As SqlParameter
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Parameters(0) = New SqlParameter("@ParentID", _ParentID)
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Parameters(1) = New SqlParameter("@Value", _Value)
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Parameters(3) = New SqlParameter("@Order", _Order)
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Parameters(4) = New SqlParameter("@Original_ID", _ID)
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Update(SqlTxt, Parameters)
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Catch ex As Exception
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Throw
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End Try
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End Sub
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Protected Overrides Sub Finalize()
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MyBase.Finalize()
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End Sub
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End Class

再來設計一個配合存取資料的BLL.daoMenu，進行新增、修改、刪除、查詢的動作

Public Class daoMenu
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Public Function GetMenu() As List(Of DAL.objMenu)
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Try
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Dim rMenu As New List(Of DAL.objMenu)
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rMenu.Clear()
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Dim oData As New DAL.objData()
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Dim SqlTxt As String = "SELECT * FROM Menu ORDER BY [Order]"
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Dim dt As New DataTable
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If oData.SqlSelectQuery(SqlTxt, dt) Then
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For Each row As DataRow In dt.Rows
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rMenu.Add(New DAL.objMenu(row))
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Next
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End If
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Return rMenu
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Catch ex As Exception
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Throw
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End Try
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End Function
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Public Sub MenuUpdate(ByVal oMenu As DAL.objMenu)
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Try
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oMenu.Update()
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Catch ex As Exception
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Throw
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End Try
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End Sub
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Public Sub MenuDel(ByVal oMenu As DAL.objMenu)
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Try
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oMenu.Del()
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Catch ex As Exception
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Throw
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End Try
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End Sub
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Public Sub MenuAddNew(ByVal oMenu As DAL.objMenu)
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Try
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oMenu.Add()
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Catch ex As Exception
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Throw
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End Try
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End Sub
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End Class

再來關於GetMenu,AddRoot,AddNodes 修改如下

/// <summary>
02

/// 取得MenuTree By Phoehix - 2008
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/// </summary>
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/// <param name="MenuTree">TreeView</param>
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/// <returns>TreeView</returns>
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public bool GetMenu(out TreeView MenuTree)
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{
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MenuTree = new TreeView();
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BLL.daoMenu daoMenu = new BLL.daoMenu();
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List<DAL.objMenu> objMenu;
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objMenu = daoMenu.GetMenu();
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bool result = false;
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result = AddRoot(ref MenuTree,ref objMenu);
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if (result)
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{
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MenuTree.ImageSet = TreeViewImageSet.Custom;
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MenuTree.NodeIndent = 0;
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return true;
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}
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else
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{
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return false;
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}
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}

9-宣告 daoMenu 成為新的執行個體

10- 宣告 objMenu 為一個物件的List集合

11-從daoMenu.GetMenu() 這個方法填入objMenu

13-把參數用Ref的方式傳過去

14~ 類似的不再贅述

再來 ~AddRoot

private bool AddRoot(ref TreeView MenuTree, ref List<DAL.objMenu> objMenu)
02

{
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try
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{
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int tmpNodeID;
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List<DAL.objMenu> lists = objMenu.FindAll(delegate(DAL.objMenu list) { return list.MenuParentID == 0; });
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if (lists.Count >= 0)
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{
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TreeNode NewNode;
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bool rc;
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foreach (DAL.objMenu list in lists)
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{
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NewNode = new TreeNode();
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tmpNodeID = list.MenuID;
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NewNode.Text = list.MenuValue;
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MenuTree.Nodes.Add(NewNode);
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rc = AddNodes(ref NewNode, tmpNodeID, ref objMenu);
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}
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}
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lists = null;
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return true;
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}
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catch
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{
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return false;
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}
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}

修改的部份為

6- 有趣有趣 ... 先宣告一個lists 來承接 objMenu.FindAll 出來的結果 (厄!? 其實我忘記這是哪邊看來的 ...

這裡重點就是在delegate(DAL.objMenu list) { return list.MenuParentID == 0; } 意思是傳回 MenuParentID = 0(跟節點)

9-判斷是否有資料

11-把資料一一的取出

13-15 把資料填入

19-傳objMenu過去一樣用ref方式 (應該是可以節省複製一份出來的記憶體 ...)

22-告訴.NET 我不要lists 了= =、

最後AddNodes

private bool AddNodes(ref TreeNode tNode, int PID, ref List<DAL.objMenu> objMenu)
02

{
03

try
04

{
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int tmpNodeID;
06

List<DAL.objMenu> lists = objMenu.FindAll(delegate(DAL.objMenu list) { return list.MenuParentID == PID; });
07

if (lists.Count >=0)
08

{
09

TreeNode NewNode;
10

bool rc;
11

foreach (DAL.objMenu list in lists)
12

{
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NewNode = new TreeNode();
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tmpNodeID = list.MenuID;
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NewNode.Text = list.MenuValue;
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tNode.ChildNodes.Add(NewNode);
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rc = AddNodes(ref NewNode, tmpNodeID, ref objMenu);
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}
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}
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lists = null;
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return true;
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}
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catch
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{
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return false;
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}
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}

修改的部份如下

6- 跟上面差不多只是 ParentID 要改用傳過來的節點代號篩選出該節點的子節點

11-foreach一一取出資料

13~15 填入資料

然後就完成囉！

當然 ... 顯示出來的結果會是一樣的

以上 ~ 我覺得比較值得一提的是 LIST<T>.FindAll 這個方法 ... 蠻有趣的呢~ 大家可以參考MSDN ->List<(Of <(T>)>)..::.FindAll 方法

Phoenix 8/5

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