ASP.NET中不定级动态菜单的实现

前日，根据客户需要，要根据如下的表动态生成如下的菜单：表中的数据是动态更新的。

我们平时IEWebContr来做菜单时都是在html中直接输入，也就是说是静态的，现在要做成动态的，而且菜单级数不定，怎么来实现呢？笔者通过研究发现，用IEWebContr来做菜单时，菜单项可以直接输入，也可以用如下的方法指定从某一个文件中读取菜单项：

　<iewc:TreeViewrunat="server"ID="Treeview1"NAME="Treeview1">
<iewc:TreeNodeid="Treenode1"runat="server"TreeNodeSrc="menuone.txt"Expanded="True"Text="信息类别列表"></iewc:TreeNode>
</iewc:TreeView>

其中menuone.txt的内容如下：

<TREENODES>
<treenodetext='蔬菜'NavigateUrl='xxcb_add.aspx?classname=蔬菜&classid=01'?Target='main1'>
<treenodetext='白菜'NavigateUrl='xxcb_add.aspx?classname=白菜&classid=0101'??Target='main1'/>
<treenodetext='萝卜'NavigateUrl='xxcb_add.aspx?classname=萝卜&classid=0102'??Target='main1'/>
<treenodetext='黄花菜'NavigateUrl='xxcb_add.aspx?classname=黄花菜&classid=0103'??Target='main1'/>
</treenode>
<treenodetext='水果'NavigateUrl='xxcb_add.aspx?classname=水果&classid=02'?Target='main1'>
<treenodetext='苹果'NavigateUrl='xxcb_add.aspx?classname=苹果&classid=0201'?Target='main1'>
<treenodetext='红富士'NavigateUrl='xxcb_add.aspx?classname=红富士&classid=020101'??Target='main1'/>
<treenodetext='其它苹果'NavigateUrl='xxcb_add.aspx?classname=其它苹果&classid=020102'??Target='main1'/>

　</treenode>
<treenodetext='桃子'NavigateUrl='xxcb_add.aspx?classname=桃子&classid=0202'??Target='main1'/>
<treenodetext='荔枝'NavigateUrl='xxcb_add.aspx?classname=荔枝&classid=0203'??Target='main1'/>
</treenode>
<treenodetext='粮食'NavigateUrl='xxcb_add.aspx?classname=粮食&classid=03'?Target='main1'>
<treenodetext='大米'NavigateUrl='xxcb_add.aspx?classname=大米&classid=0301'??Target='main1'/>
<treenodetext='玉米'NavigateUrl='xxcb_add.aspx?classname=玉米&classid=0302'??Target='main1'/>
</treenode>
</TREENODES>

现在的问题变成了如何将数据表根据“类别号”修改menuone.txt文件。将该过程放在对数据表修改后进行。下面是根据表的内容生成menuone.txt的源代码：

　ImportsSystem.IO
DimtxtwriterAsStreamWriter
txtwriter=File.CreateText(Server.MapPathstrpath("/menuone.txt"))
txtwriter.WriteLine("<TREENODES>")

DimobjConnAsOleDbConnection
DimobjCmdAsOleDbCommand
DimobjReadAsOleDbDataReader
DimstrSQL,strDSNAsString
Dimstrid,strname,strid1,strname1AsString
DimstrandAsString
strand="&amp;"

Dimi,j,k,mAsInteger
i=0
j=0
k=0
m=0

strSQL="select*fromclassorderbyclassid"

objConn=NewOleDbConnection(ConfigurationSettings.AppSettings("connString"))
objCmd=NewOleDbCommand(strSQL,objConn)
objCmd.Connection.Open()
objRead=objCmd.ExecuteReader()

WhileobjRead.Read()

Ifj=0Then
j=Len(Trim(objRead.Item("classid")))
Else
strid=strid1
strname=strname1
i=Len(Trim(objRead.Item("classid")))

k=i-j

SelectCasek
CaseIs>0
txtwriter.WriteLine("<treenodetext='"&strname&"'NavigateUrl='xxcb_add.aspx?classname="&strname&""&strand&"classid="&strid&"'Target='main1'>")
CaseIs=0
txtwriter.WriteLine("<treenodetext='"&strname&"'NavigateUrl='xxcb_add.aspx?classname="&strname&""&strand&"classid="&strid&"'Target='main1'/>")
CaseIs<0
txtwriter.WriteLine("<treenodetext='"&strname&"'NavigateUrl='xxcb_add.aspx?classname="&strname&""&strand&"classid="&strid&"'Target='main1'/>")
'txtwriter.WriteLine("</treenode>")

m=k
Whilem<0
txtwriter.WriteLine("</treenode>")
m=m+2
EndWhile

EndSelect

j=Len(Trim(objRead.Item("classid")))

EndIf

strid1=Trim(objRead.Item("classid"))
strname1=Trim(objRead.Item("classname"))

EndWhile

'strid=strid1
'strname=strname1
i=Len(strid)
k=j-i
strid=strid1
strname=strname1
SelectCasek
CaseIs>0
txtwriter.WriteLine("<treenodetext='"&strname&"'NavigateUrl='xxcb_add.aspx?classname="&strname&""&strand&"classid="&strid&"'Target='main1'/>")
'txtwriter.WriteLine("</treenode>")

m=Len(strid)/2

Whilem>1
txtwriter.WriteLine("</treenode>")
m=m-1
EndWhile
CaseIs=0
txtwriter.WriteLine("<treenodetext='"&strname&"'NavigateUrl='xxcb_add.aspx?classname="&strname&""&strand&"classid="&strid&"'Target='main1'/>")
'txtwriter.WriteLine("</treenode>")
m=Len(strid)/2

Whilem>1
txtwriter.WriteLine("</treenode>")
m=m-1
EndWhile
CaseIs<=0
txtwriter.WriteLine("<treenodetext='"&strname&"'NavigateUrl='xxcb_add.aspx?classname="&strname&""&strand&"classid="&strid&"'Target='main1'/>")
'txtwriter.WriteLine("</treenode>")

m=Len(strid)/2

Whilem>1
txtwriter.WriteLine("</treenode>")
m=m-1
EndWhile

EndSelect
txtwriter.WriteLine("</TREENODES>")
txtwriter.Close()

这样menuone.txt就按要求生成了菜单源文件。