ASP.NET中不定级动态菜单的实现 (1)

作者xiangwa 出处CSDN

　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

　 %26lt;iewc:TreeView runat="server" ID="Treeview1" NAME="Treeview1"%26gt;
　　%26lt;iewc:TreeNode id="Treenode1" runat="server" TreeNodeSrc="menuone.txt" Expanded="True" Text="信息类别列表"%26gt;%26lt;/iewc:TreeNode%26gt;
　　%26lt;/iewc:TreeView%26gt;

　　其中menuone.txt的内容如下

　　%26lt;TREENODES%26gt;
　　%26lt;treenode text='蔬菜' NavigateUrl='xxcb_add.aspx?classname=蔬菜%26amp;classid=01'? Target='main1'%26gt;
　　%26lt;treenode text='白菜' NavigateUrl='xxcb_add.aspx?classname=白菜%26amp;classid=0101'?? Target='main1'/%26gt;
　　%26lt;treenode text='萝卜' NavigateUrl='xxcb_add.aspx?classname=萝卜%26amp;classid=0102'?? Target='main1'/%26gt;
　　%26lt;treenode text='黄花菜' NavigateUrl='xxcb_add.aspx?classname=黄花菜%26amp;classid=0103'?? Target='main1'/%26gt;
　　%26lt;/treenode%26gt;
　　%26lt;treenode text='水果' NavigateUrl='xxcb_add.aspx?classname=水果%26amp;classid=02'? Target='main1'%26gt;
　　%26lt;treenode text='苹果' NavigateUrl='xxcb_add.aspx?classname=苹果%26amp;classid=0201'? Target='main1'%26gt;
　　%26lt;treenode text='红富士' NavigateUrl='xxcb_add.aspx?classname=红富士%26amp;classid=020101'?? Target='main1'/%26gt;
　　%26lt;treenode text='其它苹果' NavigateUrl='xxcb_add.aspx?classname=其它苹果%26amp;classid=020102'?? Target='main1'/%26gt;

　 %26lt;/treenode%26gt;
　　%26lt;treenode text='桃子' NavigateUrl='xxcb_add.aspx?classname=桃子%26amp;classid=0202'?? Target='main1'/%26gt;
　　%26lt;treenode text='荔枝' NavigateUrl='xxcb_add.aspx?classname=荔枝%26amp;classid=0203'?? Target='main1'/%26gt;
　　%26lt;/treenode%26gt;
　　%26lt;treenode text='粮食' NavigateUrl='xxcb_add.aspx?classname=粮食%26amp;classid=03'? Target='main1'%26gt;
　　%26lt;treenode text='大米' NavigateUrl='xxcb_add.aspx?classname=大米%26amp;classid=0301'?? Target='main1'/%26gt;
　　%26lt;treenode text='玉米' NavigateUrl='xxcb_add.aspx?classname=玉米%26amp;classid=0302'?? Target='main1'/%26gt;
　　%26lt;/treenode%26gt;
　　%26lt;/TREENODES%26gt;

　　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

　 Imports System.IO
　　Dim txtwriter As StreamWriter
　　txtwriter = File.CreateText(Server.MapPathstrpath ("\menuone.txt"))
　　txtwriter.WriteLine("%26lt;TREENODES%26gt;")

　　Dim objConn As OleDbConnection
　　Dim objCmd As OleDbCommand
　　Dim objRead As OleDbDataReader
　　Dim strSQL, strDSN As String
　　Dim strid, strname, strid1, strname1 As String
　　Dim strand As String
　　strand = "%26amp;amp;"


　　Dim i, j, k, m As Integer
　　i = 0
　　j = 0
　　k = 0
　　m = 0

　　strSQL = "select * from class order by classid "

　　objConn = New OleDbConnection(ConfigurationSettings.AppSettings("connString"))
　　objCmd = New OleDbCommand(strSQL, objConn)
　　objCmd.Connection.Open()
　　objRead = objCmd.ExecuteReader()

　　While objRead.Read()

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

　　k = i - j

　　Select Case k
　　Case Is %26gt; 0
　　txtwriter.WriteLine("%26lt;treenode text='" %26amp; strname %26amp; "' NavigateUrl='xxcb_add.aspx?classname=" %26amp; strname %26amp; "" %26amp; strand %26amp; "classid=" %26amp; strid %26amp; "' Target='main1'%26gt;")
　　Case Is = 0
　　txtwriter.WriteLine("%26lt;treenode text='" %26amp; strname %26amp; "' NavigateUrl='xxcb_add.aspx?classname=" %26amp; strname %26amp; "" %26amp; strand %26amp; "classid=" %26amp; strid %26amp; "' Target='main1'/%26gt;")
　　Case Is %26lt; 0
　　txtwriter.WriteLine("%26lt;treenode text='" %26amp; strname %26amp; "' NavigateUrl='xxcb_add.aspx?classname=" %26amp; strname %26amp; "" %26amp; strand %26amp; "classid=" %26amp; strid %26amp; "' Target='main1'/%26gt;")
　　'txtwriter.WriteLine("%26lt;/treenode%26gt;")

　　m = k
　　While m %26lt; 0
　　txtwriter.WriteLine("%26lt;/treenode%26gt;")
　　m = m + 2
　　End While

　　End Select

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

　　End If

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

　　End While

　　'strid = strid1
　　'strname = strname1
　　i = Len(strid)
　　k = j - i
　　strid = strid1
　　strname = strname1
　　Select Case k
　　Case Is %26gt; 0
　　txtwriter.WriteLine("%26lt;treenode text='" %26amp; strname %26amp; "' NavigateUrl='xxcb_add.aspx?classname=" %26amp; strname %26amp; "" %26amp; strand %26amp; "classid=" %26amp; strid %26amp; "' Target='main1'/%26gt;")
　　'txtwriter.WriteLine("%26lt;/treenode%26gt;")

　　m = Len(strid) / 2

　　While m %26gt; 1
　　txtwriter.WriteLine("%26lt;/treenode%26gt;")
　　m = m - 1
　　End While
　　Case Is = 0
　　txtwriter.WriteLine("%26lt;treenode text='" %26amp; strname %26amp; "' NavigateUrl='xxcb_add.aspx?classname=" %26amp; strname %26amp; "" %26amp; strand %26amp; "classid=" %26amp; strid %26amp; "' Target='main1'/%26gt;")
　　'txtwriter.WriteLine("%26lt;/treenode%26gt;")
　　m = Len(strid) / 2

　　While m %26gt; 1
　　txtwriter.WriteLine("%26lt;/treenode%26gt;")
　　m = m - 1
　　End While
　　Case Is %26lt;= 0
　　txtwriter.WriteLine("%26lt;treenode text='" %26amp; strname %26amp; "' NavigateUrl='xxcb_add.aspx?classname=" %26amp; strname %26amp; "" %26amp; strand %26amp; "classid=" %26amp; strid %26amp; "' Target='main1'/%26gt;")
　　'txtwriter.WriteLine("%26lt;/treenode%26gt;")

　　m = Len(strid) / 2

　　While m %26gt; 1
　　txtwriter.WriteLine("%26lt;/treenode%26gt;")
　　m = m - 1
　　End While

　　End Select
　　txtwriter.WriteLine("%26lt;/TREENODES%26gt;")
　　txtwriter.Close()

　　这样menuone.txt就按要求生成了菜单源文件。