利用VB.NET设计Web菜单组件

Windows应用程序中往往离不开菜单，菜单的应用是十分普遍了，并且菜单的设计是十分简单的，这主要是因为它已经被编制成组件封装在编程语言中可供直接调用。可是Web程序中要直接用到可供调用的菜单是不可能的，它要编写许多复杂的代码。所以许多WEB程序设计者尽可能避免这些麻烦，用其它功能代替。可是，这样会影响WEB风格甚至降低程序的水准。事实，我们同样可以借签Windows的菜单设计经验开发一个完整的Web菜单组件，全面封装后供用户直接调用，其使用的方便完全与Windows的菜单一样。本人在实践中利用VBasic.Net开发出一个仿真WINDOW菜单，实现WEB上的多级菜单组件。该组件具有灵活、动态、多效果功能，用户可以根据需要设计不同风格的菜单，支持图标，选择行、菜单风格的自设置；图标背景，背景图片，前背景、动态提示、字体、文字、快捷键等设置。现在把它实现的方法及过程阐述如下：

实现原理：利用VBasic.Net强大的组件开发功能，把每个菜单行作为一个结点，设置结点的不同属性。在菜单组件的自定义事件中控制菜单所显示的内容，调用对应功能。

开发步骤如下：

一、启动Visual Studio.NET。在新建项目中选择Visual Basic项目，在模板中选择类库，在名称中输入类库文件名如MenuNode确定，则进入类库开发环境中，把Class1换名为MenuNode.

二、定义公共类MenuNode，该类为供应用软件调用。定义类MenuNode的私有变量_ImageUrl，该变量表示结点图片。定义类MenuNode的属性_ParentID，该属性父结点号，分别编写它们的功能。代码如下：

Public Class MenuNode : Inherits TableCell

Private _ImageUrl As String

Private _ParentID As Int16

’父结点号

Public Property ParentID() As Int16

Get

Return ViewState("_ParentID")

End Get

Set(ByVal Value As Int16)

ViewState("_ParentID") = Value

Dim a As TableCell

End Set

End Property

’结点图片

Public Property ImageUrl() As String

Get

Return ViewState("_ImageUrl")

End Get

Set(ByVal Value As String)

ViewState("_ImageUrl") = Value

End Set

End Property

End Class

三、定义公共类MenuView，该类定义菜单的主体，属性，方法

1、定义MenuView类，该类继承WebControl类。由于MenuView类是一个用户自定义类，我们要自定义自己的事件。所以它还需要引用INamingContainer(唯一命名空间接口), IPostBackEventHandler(自定义事件接口)

代码如下：

Public Class MenuView : Inherits WebControl

Implements INamingContainer

Implements IPostBackEventHandler

2、定义MenuView类的一些属性

’背景图片

Dim _BackGround As String

’风格类型

Dim _Type As Int16

’集合下标从1开始，用集合来存放菜单项

Public Shared coll As New Collection()

’定义菜单项的类型：图标型、检测型、检测背景型、普通型

Enum EType

IsImageBackColor = 0

IsCheckBackColor = 1

IsCheck = 2

None = 3

End Enum

’菜单表

Public Shared Index As Int16

’所选择的菜单项指针

Dim _SelectIndex As Int16

’所选择的菜单项背景色

Dim _SelectBackColor As System.Drawing.Color

’图标背景色

Dim _IconBackColor As System.Drawing.Color

Public Property SelectIndex() As Int16

Get

Return _SelectIndex

End Get

Set(ByVal Value As Int16)

End Set

End Property

Public Property SelectBorderStyle() As BorderStyle

Get

Return ViewState("_SelectBorderStyle")

End Get

Set(ByVal Value As BorderStyle)

ViewState("_SelectBorderStyle") = Value

End Set

End Property

Public Property SelectBackColor() As System.Drawing.Color

Get

Return ViewState("_SelectBackColor")

End Get

Set(ByVal Value As System.Drawing.Color)

ViewState("_SelectBackColor") = Value

End Set

End Property

Public Property IconBackColor() As System.Drawing.Color

Get

Return ViewState("_IconBackColor")

End Get

Set(ByVal Value As System.Drawing.Color)

ViewState("_IconBackColor") = Value

End Set

End Property

’

Public Property Type() As EType

Get

Return ViewState("_Type")

End Get

Set(ByVal Value As EType)

ViewState("_Type") = Value

End Set

End Property

Public Property BackGround() As String

Get

Return ViewState("_BackGround")

End Get

Set(ByVal Value As String)

ViewState("_BackGround") = Value

End Set

End Property

3、定义MenuView类的一些方法

’初使化菜单

Public Sub New()

Me.BackColor = System.Drawing.Color.DeepPink

Me.BorderStyle = BorderStyle.Outset

Me.Width = Unit.Pixel(250)

’Me.Width = Unit.Pixel(50)

Me.BackGround = ""

Me.BorderWidth = Unit.Pixel(0)

Me.Type = 1

End Sub

’自定义OnChange事件，该事件用来表示用户所调用菜单项所完成的功能

Public Event Change As EventHandler

’触发OnChange事件。

Protected Overridable Sub OnChange(ByVal e As EventArgs)

RaiseEvent Change(Me, e)

End Sub

’ 当由类实现时，使服务器控件能够处理将窗体发送到服务器时引发的事件。

Public Sub RaisePostBackEvent(ByVal eventArgument As String) Implements IPostBackEventHandler.RaisePostBackEvent

OnChange(New EventArgs())

End Sub

’通过Render方法把组件中的源码直接输出到html文件中,在客户端让IE直接执行。主要要判定出用户所选择的菜单项，分情况处理。显示该菜单体，隐藏其它菜单体。

’ /// <summary>

’/// 将此控件呈现给指定的输出参数。

’/// </summary>

’/// <param name="output"> 要写出到的 HTML 编写器 </param>

Protected Overrides Sub Render(ByVal output As System.Web.UI.HtmlTextWriter)

MyBase.Render(output)

output.Write(Chr(13) + Chr(10))

Dim str As String

str = "<script language=’javascript’> " + Chr(13) + Chr(10) & _

"function OpenTable(obj1,index,Type){ " + Chr(13) + Chr(10) & _

" var obj,coll,MenuObj,PareObj; " + Chr(13) + Chr(10) & _

" switch ( Type){ " + Chr(13) + Chr(10) & _

" case 0: //’下菜单 " + Chr(13) + Chr(10) & _

" PareObj=obj1.offsetParent; MenuObj=PareObj.offsetParent; break; " + Chr(13) + Chr(10) & _

" case 1: //’左菜单 " + Chr(13) + Chr(10) & _

" PareObj=obj1.offsetParent; MenuObj=PareObj.offsetParent; break; " + Chr(13) + Chr(10) & _

" case 2: // ’无菜单 " + Chr(13) + Chr(10) & _

" PareObj=obj1.offsetParent;MenuObj=PareObj.offsetParent; break;" + Chr(13) + Chr(10) & _

" case 3: " + Chr(13) + Chr(10) & _

" coll=obj1.all.tags(’TABLE’); " + Chr(13) + Chr(10) & _

" for (i=1;i<coll.length;i++) " + Chr(13) + Chr(10) & _

" coll[i].style.visibility=’hidden’;return; " + Chr(13) + Chr(10) & _

" case 4: //’Form " + Chr(13) + Chr(10) & _

" coll= document.all.tags(’span’); " + Chr(13) + Chr(10) & _

" for (i=0;i<coll.length ;i++) " + Chr(13) + Chr(10) & _

" { a=coll[i].id.split(’_’); " + Chr(13) + Chr(10) & _

" if (a[a.length-1]==obj1) break; } //window.alert (obj1);//var obj1=document.getElementById(obj1); " + Chr(13) + Chr(10) & _

" obj1=coll[i];coll=obj1.all.tags(’TABLE’); " + Chr(13) + Chr(10) & _

" for (i=1;i<coll.length;i++) " + Chr(13) + Chr(10) & _

" coll[i].style.visibility=’hidden’; return;} " + Chr(13) + Chr(10) & _

" coll=MenuObj.all.tags(’TABLE’);" + Chr(13) + Chr(10) & _

" for (i=0;i<coll.length;i++) " + Chr(13) + Chr(10) & _

" if (coll[i] ==PareObj ) break; " + Chr(13) + Chr(10) & _

" obj=coll[i+index+1]; " + Chr(13) + Chr(10) & _

" for (j=i+2;j<coll.length;j++) " + Chr(13) + Chr(10) & _

" coll[j].style.visibility=’hidden’; " + Chr(13) + Chr(10) & _

" if (Type==2) return; " + Chr(13) + Chr(10) & _

" var top,left,hight,width; " + Chr(13) + Chr(10) & _

" top=obj1.offsetTop;left=obj1.offsetLeft;hight=obj1.offsetHeight; width=obj1.offsetWidth; " + Chr(13) + Chr(10) & _

" while(obj1=obj1.offsetParent) " + Chr(13) + Chr(10) & _

" { top+=obj1.offsetTop; left+=obj1.offsetLeft; } " + Chr(13) + Chr(10) & _

" var PareLeft=obj.offsetParent.offsetLeft;PareTop=obj.offsetParent.offsetTop;PareWidth=obj.offsetWidth; " + Chr(13) + Chr(10) & _

" if (Type==0) " + Chr(13) + Chr(10) & _

" {obj.style.top=top+hight-PareTop; obj.style.left=left-PareLeft;} " + Chr(13) + Chr(10) & _

" else {obj.style.top=top-PareTop; obj.style.left=left+width-PareLeft;} " + Chr(13) + Chr(10) & _

" obj.style.visibility=’visible’; " + Chr(13) + Chr(10) & _

" } " + Chr(13) + Chr(10) & _

" </script>" + Chr(13) + Chr(10 output.Write(str)

End Sub

’通知使用基于合成的实现的服务器控件创建它们包含的任何子控件，以便为回发或呈现做准备。

Protected Overrides Sub CreateChildControls()

’生成主菜单

Dim MainTable As New Table()

Dim MainNodes() As MenuNode

MainNodes = Me.GetSubNodes(0)

MainTable = CreateMainMenu(MainNodes)

Me.Controls.Add(MainTable)

’得到子菜单数及每个子菜单的行数

Dim subCount As Int16 = MainNodes.Length - 1

’递规生成子菜单

Dim i As Int16

For i = 0 To subCount - 1

CreateSubMenu(MainNodes(i).ID)

’ 透明处理

Me.Attributes("style") = Me.Attributes("style") + ";background-color: transparent "

Me.Attributes("onclick") = "OpenTable(this ,0,3 )"

Dim Form1 = cls.GetParent(Me, "HtmlForm")

Form1.Attributes("onclick") = "OpenTable(’" + Me.ID + "’,0,4 )"

Me.BorderWidth = Unit.Pixel(0)

’For i = 1 To Me.coll.Count

’ Me.coll.Remove(1)

’Next

End Sub

’生成主菜单。由结点生成菜单体

Private Function CreateMainMenu(ByVal Nodes() As MenuNode) As Table

Dim i, j As Int16

’计算父菜单数(及面板数),子菜单数

Dim Count As Int16 = Nodes.Length - 1

Dim Table1 As New Table()

Table1 = Me.CreateTable(1, 2 * Count - 1)

Me.SetTableStyle(Table1)

’生成主表

For i = 0 To Count - 1

Dim Node As New MenuNode()

Node = Nodes(i)

Dim Cell1 As New TableCell()

j = 2 * i

Cell1 = Table1.Rows(0).Cells(j)

’是否有图片,有则生成图片对象，否则生成Label代替

If Node.ImageUrl <> "" Then

Cell1.Controls.Add(Me.CreateImage(Node))

End If

Me.SetCellStyle(Cell1, Node)

’Dim SubName As String

’SubName = Me.ID + "_" + "T%" + Node.ID ’i.ToString

’ Me.Parent.Parent.Parent.Parent.Controls()

’鼠标经过时把所有子菜单隐藏(, 把所对应的子菜单显示)

If Me.HasSub(Node) Then

Cell1.Attributes("onmouseover") = "this.style.background=’" + Me.GetColorValue(SelectBackColor) + "’;OpenTable(this," + i.ToString + ",0 )"

Else

Cell1.Attributes("onmouseover") = "this.style.background=’" + Me.GetColorValue(SelectBackColor) + "’;OpenTable(this," + i.ToString + ",2 )"

Dim button1 As New LinkButton()

button1.ID = Nodes(i).ID

Me.Controls.Add(button1)

button1.CommandArgument = Nodes(i).ID.ToString

AddHandler button1.Click, AddressOf TableRow_Click

Cell1.Attributes("onclick") = "javascript:__doPostBack(’" + Me.ID + ":" + button1.ID + "’,’’)"

End If

Cell1.Attributes("onmouseout") = "this.style.background=’" + Me.GetColorValue(Me.BackColor) + "’"

If i < Count - 1 Then

Table1.Rows(0).Cells(2 * i + 1).Width = Unit.Pixel(25)

End If

If Table1.Rows(0).Cells.Count > 0 Then

Table1.Rows(0).Cells(0).ID = "Cell0"

End If

Table1.ID = "T%"

Return Table1

End Function

’递归生成子菜单

Private Sub CreateSubMenu(ByVal ID As Int16)

Dim Nodes() As MenuNode

Nodes = Me.GetSubNodes(ID)

Dim Count As Int16 = Nodes.Length - 1

Dim TableRow(Count) As TableRow

’计算父菜单数(及面板数),子菜单数

Dim Table1 As New Table()

Me.SetTableStyle(Table1)

Dim i As Int16

For i = 0 To Count - 1

Dim Node As New MenuNode()

Node = Nodes(i)

TableRow(i) = New TableRow()

TableRow(i) = Me.CreateMenuItem(Node)

’Dim SubName As String

’SubName = Me.ID + "_" + "T%" + Node.ID ’ (Index + Count - 1).ToString

’鼠标经过时把所有子菜单隐藏，把所对应的子菜单显示

If Me.HasSub(Node) Then

TableRow(i).Attributes("onmouseover") = "this.style.background=’" + Me.GetColorValue(SelectBackColor) + "’;OpenTable(this," + i.ToString + " ,1 )"

Else

TableRow(i).Attributes("onmouseover") = "this.style.background=’" + Me.GetColorValue(SelectBackColor) + "’;OpenTable(this," + i.ToString + " ,2 )"

Dim button1 As New LinkButton()

button1.ID = Nodes(i).ID

Me.Controls.Add(button1)

button1.CommandArgument = Nodes(i).ID.ToString

AddHandler button1.Click, AddressOf TableRow_Click

If Me.Type = EType.IsCheck Or Me.Type = EType.IsCheckBackColor Then

TableRow(i).Attributes("onclick") = "this.cells(0).text=’√’; javascript:__doPostBack(’" + Me.ID + ":" + button1.ID + "’,’’)"

Else

TableRow(i).Attributes("onclick") = "javascript:__doPostBack(’" + Me.ID + ":" + button1.ID + "’,’’)"

End If

’ button1.Attributes("href") = "/"

End If

TableRow(i).Attributes("onmouseout") = "this.style.background=’" + Me.GetColorValue(Me.BackColor) + "’"

Table1.Controls.Add(TableRow(i))

Table1.Attributes("style") = "Z-INDEX:999;position:absolute;visibility:hidden ;BACKGROUND-COLOR:" + Me.GetColorValue(Me.BackColor)

Table1.ID = "T%" + ID.ToString ’Index.ToString

Index = Index + 1

Me.Controls.Add(Table1)

For i = 0 To Count - 1

ID = Nodes(i).ID

If Me.HasSub(Nodes(i)) Then

CreateSubMenu(ID)

End If

End Sub

’设置单元格风格

Private Sub SetCellStyle(ByRef cell1 As TableCell, ByVal item As MenuNode)

cell1.BorderStyle = BorderStyle.None

’cell1.BorderWidth = me.BorderStyle

cell1.Enabled = item.Enabled

’ cell1.EnableViewState = item.EnableViewState

’ cell1.Height = item.Height

cell1.TabIndex = item.TabIndex

cell1.ToolTip = item.ToolTip

cell1.Visible = item.Visible

’ cell1.BackColor = Me.BackColor

cell1.Font.Bold = Me.Font.Bold

cell1.Font.Italic = Me.Font.Italic

cell1.Font.Name = Me.Font.Name

cell1.Font.Overline = Me.Font.Overline

cell1.Font.Size = Me.Font.Size

cell1.Font.Strikeout = Me.Font.Strikeout

cell1.Font.Underline = Me.Font.Underline

cell1.ForeColor = Me.ForeColor

cell1.Text = GetHotKeyText(item)

cell1.Wrap = False

End Sub

’设置表的风格

Private Sub SetTableStyle(ByRef Table1 As Table)

’其父是透明的则得到的是其父的父的颜色

’Table1.BorderColor = Me.BackColor ’ System.Drawing.Color.White ’ .Blue

Table1.Attributes("style") = "Z-INDEX:999;BACKGROUND-COLOR:" + Me.GetColorValue(Me.BackColor)

Table1.Attributes("onmouseover") = "this.style.cursor=’hand’"

’ Table1.Page.Application.

Table1.BorderColor = Me.BorderColor

Table1.BorderStyle = Me.BorderStyle

Table1.BorderWidth = Unit.Pixel(2)

Table1.Enabled = Me.Enabled

Table1.EnableViewState = Me.EnableViewState

Table1.TabIndex = Me.TabIndex

Table1.ToolTip = Me.ToolTip

Table1.Visible = Me.Visible

Table1.CellPadding = 0

Table1.CellSpacing = 0

End Sub

’生成表格 (row*col)

Private Function CreateTable(ByVal row As Int16, ByVal col As Int16) As Table

Dim Table1 As New Table()

Table1.BackImageUrl = Me.BackGround

Dim i, j As Int16

For i = 0 To row - 1

Dim r As New TableRow()

r = Me.CreateTableRow(col)

Table1.Rows.Add(r)

Table1.Attributes("onmouseover") = "this.style.cursor=’hand’"

Return Table1

End Function

’建立菜单项

Private Function CreateMenuItem(ByVal item As MenuNode) As TableRow

Dim TableRow1 As New TableRow()

TableRow1 = Me.CreateTableRow(3)

Select Case Me._Type

Case 0 To 2 ’image

TableRow1.Cells(0).BackColor = IconBackColor

’ TableRow1.Cells(0).Text = "√"

’ Case 1 ’check

Case 3 ’

End Select

’填充数据

’第一列

’是否有图片,有则生成图片对象，否则生成Label代替

If item.ImageUrl <> "" Then

TableRow1.Cells(0).Controls.Add(Me.CreateImage(item))

End If

TableRow1.Cells(0).Width = Unit.Pixel(22)

’第二列

Me.SetCellStyle(TableRow1.Cells(1), item)

’第三列

TableRow1.Cells(2).Width = Unit.Pixel(30)

If Me.HasSub(item) Then

TableRow1.Cells(2).HorizontalAlign = HorizontalAlign.Right

Me.SetCellStyle(TableRow1.Cells(2), item)

TableRow1.Cells(2).Text = "&#9654"

End If

Return TableRow1

End Function

’是否有热键,返回有热键的文本

Private Function GetHotKeyText(ByVal item As MenuNode) As String

Dim text As String

text = item.Text

If item.AccessKey <> Nothing Then

text = text + "(<U>" + item.AccessKey + "</U>)"

End If

Return text

End Function

’建立表行(1行，n列)

Private Function CreateTableRow(ByVal n As Int16) As TableRow

Dim TableRow1 As New TableRow()

Dim i As Int16

For i = 0 To n - 1

Dim c As New TableCell()

’Me.SetCellStyle(c)

TableRow1.Cells.Add(c)

Return TableRow1

End Function

’当前索引放在最后一个位置

Private Function GetSubName(ByVal index As Int16, ByVal Count As Int16) As String

Dim i As Int16

Dim Names As String

For i = 0 To Count - 1

Names = Names + Me.ID + "_T" + i.ToString + "|"

Names = Names + Me.ID + "_T" + index.ToString

Return Names

End Function

’由生成一个图标组件

Private Function CreateImage(ByVal item As MenuNode) As Image

Dim Image1 As New Image()

Image1.ImageUrl = item.ImageUrl

’Image1.Enabled = item.Enabled

’Image1.Visible = item.Visible

Return Image1

End Function

Private Sub TableRow_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)

Dim ID As String = Trim(sender.CommandArgument)

’MessageBox(ID)

_SelectIndex = CType(ID, Int16)

OnChange(e)

End Sub

Private Function HasSub(ByVal item As MenuNode) As Boolean

Dim i As Int16

For i = 1 To coll.Count

If coll.Item(i).ParentID = item.ID Then

Return True

End If

Return False

End Function

’取得ID的所有子结点

Private Function GetSubNodes(ByVal ID As Int16) As MenuNode()

Dim i, j, SubCount As Int16

’计算子菜单数

For i = 1 To coll.Count

If coll.Item(i).ParentID = ID Then

SubCount = SubCount + 1

End If

Dim SubMenuNodeS(SubCount) As MenuNode

’取出子菜子菜单

If SubCount > 0 Then

For i = 1 To coll.Count

If coll.Item(i).ParentID = ID Then

SubMenuNodeS(j) = coll.Item(i)

j = j + 1

End If

Return SubMenuNodeS

End Function

’计算子菜单数

Private Function GetSubCount() As Int16

Dim i, j, SubCount As Int16

’计算父菜单数(及面板数)

For i = 1 To coll.Count

If coll.Item(i).ParentID = 0 Or coll.Item(i).ParentID = Nothing Then

SubCount = SubCount + 1

End If

Return SubCount

End Function

Private Function GetSpace(ByVal count As Short) As String

Dim TxtSb As New System.Text.StringBuilder()

Dim i As Short

For i = 0 To count - 1

TxtSb.Append(" ")

Return TxtSb.ToString

End Function

Private Function GetColorValue(ByVal color1 As System.Drawing.Color) As String

Dim ColorValue As String

Dim r As String = Hex(color1.R)

Dim g As String = Hex(color1.G)

Dim b As String = Hex(color1.B)

If r.Length = 1 Then

r = "0" + r

End If

If g.Length = 1 Then

g = "0" + g

End If

If b.Length = 1 Then

b = "0" + b

End If

ColorValue = r + g + b

Return ColorValue

End Function

’把结点增加到集合中

Public Sub AddNode(ByVal item As MenuNode)

’Dim Form1 = Me.Parent.FindControl(Me.Parent.ID)

’’ If Form1 Then

’If Not Form1.IsPostBack Then

coll.Add(item)

’End If

End Sub

Private Sub MessageBox(ByVal Text As String)

Dim Txt As String = "<script>alert(’" + Text + "’);</script>"

Me.Page.Response.Write(Txt)

End Sub

Protected Overrides Sub Finalize()

MyBase.Finalize()

End Sub

End Class

四、生成DLL文件

编写好了所有类，把它生成DLL文件就可。方法是在.net编辑环境下选择生成菜单中按生成就生成了DLL文件。然后，可以直接调用该组件了。

五、应用与测试

下面对它进行测试.步骤：

1.下载本控件。

2.在ASP.Net开发环境的工具箱中点击自定义工具箱，打开自定义工具箱。

3.选择".NET框架组件"。

4.点击浏览，找到刚下载的控件并选择之，点击打开，则控件被引入了。

5.点击确定，则控件加载到工具箱。

6.在工具箱中找到该控件并拖到页面窗体中。

7.设置菜单控件的属性(在属性窗口中)。

8.导入命名空间：Imports Liyu.Web

9.编写下面的代码。(假设菜单结点的属性存在表：dt数据表中)

Dim MenuView1 As New MenuView()

For i = 0 To dt.Rows.Count - 1

Dim MenuNode1 As New MenuNode()

MenuNode1.ID = dt.Rows(i)("ID")

MenuNode1.ParentID = dt.Rows(i)("ParentID")

MenuNode1.Text = Trim(dt.Rows(i)("text"))

If Not IsDBNull(dt.Rows(i)("AccessKey")) Then

MenuNode1.AccessKey = dt.Rows(i)("AccessKey")

End If

If Not IsDBNull(dt.Rows(i)("ToolTip")) Then

MenuNode1.ToolTip = dt.Rows(i)("ToolTip")

End If

If Not IsDBNull(dt.Rows(i)("ImageUrl")) Then

MenuNode1.ImageUrl = "tree\" + dt.Rows(i)("ImageUrl")

End If

MenuNode1.Enabled = dt.Rows(i)("Enabled")

MenuView1.AddNode(MenuNode1)Next

10.在菜单控件的OnChange事件中编写你所选择菜单要完成的功能。

Private Sub MenuView1_Change(ByVal sender As Object,

ByVal e As System.EventArgs)Handles MenuView1.Change

Dim ID As Int16

ID = Me.MenuView1.SelectIndex

Select Case ID

Case 1 ’ 首页

Case 4 ’asp.net

Case 5 ’vb.net

Case 6 ’c#

End Select

End Sub

总结：上面方法用Visual Basic.Net开发了一个Web菜单组件。其开发的复杂程度可想而知，该文开放了所有源代码，并分别作了较详细的解释，大多地方都有注释。通过对上文的学习，能使你掌握如何一个Web组件，Web菜单是怎样实现的，以及编写组件的方法技巧。并为自己深入学习.Net编程提供了多方面知识。