这个，其实比较简单
数据上来说，相当于是一个多维数组
比如，系 ：
计算机，中文，英语
然后是专业：
计算机 -> 软件工程，xxx专业 ...
中文 -> 汉语言文学，xxx专业 ...
数据库在设计上，你可以将他们都放在一个表里面，可以有这些列
id 唯一id
name 名称，可以是专业名称，也可以是系名称
parent 指定如果是专业，是数据那个系，这里可以存成系的id，
如果是系，那么这里直接填0，表示就可以
这样的话，一个demo数据
id name parent
1 计算机系 0
2 软件工程 1
这样，上边，后台的数据就这个节奏就可以满足，如果专业还有细分，那这个结构也可以满足
前台显示的时候，这里分成俩个select来显示就可以
第一个select用来显示系，查询parent为0的数据，显示到select里面就可以
第二个select用来显示系的专业，查询的时候，将第一个select的系id拿到，直接数据库里面查询parent为第一个select选择系的id的数据
demo
选择系：<select id="department" onchange="change(this)"></select>
选择专业：
<select id="professional"></select> //用js读取数据，然后生成代码
//根据parentid，读取数据，然后返回
function getData(parentId , callback){
$.ajax({
url : 'test.do',//后台数据地址
data : {parentId : parentId},//请求parentid的数据
success : function(result){
alert(result)
callback(result)
}
})
}
function renderOptions(arr , el){//生成select 的 option
el.empty()
$.each(data , function(index , item){
$('<option/>').attr({
value : item.id
}).html(item.name).appendTo(el)
})
}
var department = $('#department')//系的select
getData(0 , function(data){//请求系的数据
department.empty()
renderOptions(data , department)//这里生成系的select
})
var professional = $('#professional')//专业的select
function change(el){//当系变化的时候
var parentId = $(el).val()//这里得到选择的系的id
getData(parentId , function(data){
professional.empty()
renderOptions(data , professional )//这里生成专业的select
})
}
就是这样的原理
后台还需要一个查询，就是根据parentid查询数据，就可以了
1。sevice层：/**
* 构建 点取筛取 树形动态菜单
* @return tree
* @throws BasicException
*/
public String buildTree()throws BasicException{
try {
StringBuffer xmlBuffer = new StringBuffer()
int a = 0
xmlBuffer.append("d.add(0,-1,'<input type=\"checkbox\" name=\"ckb\" id=\"0\" onClick=\"check(this.form.ckb)\" value=\"-1\"/>全部')")
xmlBuffer.append("\n")
List list = getDao().findFundInvestType()
if(list!=null&&list.size()!=0){
int b = 0
for(int i=0i<list.size()i++){
FundInvestType bean = (FundInvestType)list.get(i)
String code = bean.getInvestCode()
// if is sencond
if(code.length()==2){
b++
a=i
xmlBuffer.append("d.add("+b+",0,'<input type=\"checkbox\" name=\"ckb\" id=\"0"+b+"\" onClick=\"selectAll(this.form.ckb,this.id)\" value=\""+bean.getInvestCode()+"\" /><b>"+bean.getInvestName()+"</b>','')")
xmlBuffer.append("\n")
}else if(code.length()==10){
//if is second
if(code.substring(2,10).equals("00000000")){
b++
a=i
xmlBuffer.append("d.add("+b+",0,'<input type=\"checkbox\" name=\"ckb\" id=\"0"+b+"\" onClick=\"selectAll(this.form.ckb,this.id)\" value=\""+bean.getInvestCode()+"\"/><b>"+bean.getInvestName()+"</b>','')")
xmlBuffer.append("\n")
}else{//if is third,it father is second
b++
int k = a+1
xmlBuffer.append("d.add("+b+","+k+",'<input type=\"checkbox\" name=\"ckb\" id=\"ckb0"+k+"\" value=\""+bean.getInvestCode()+"\"/>"+bean.getInvestName()+"','')")
xmlBuffer.append("\n")
}
}
}
}
return xmlBuffer.toString()
} catch (RuntimeException e) {
throw new BasicException(e.getMessage())
}
}
2。jsp页面：
<%@ page contentType="text/htmlcharset=utf-8" language="java" import="java.sql.*" errorPage="" %>
<%
String webapp=request.getContextPath()+"/fund"
%>
<html >
<head>
<meta http-equiv="Content-Type" content="text/htmlcharset=utf-8" />
<title>基金投资类型</title>
<link rel="stylesheet" type="text/css" href="<%=webapp%>/Pub/Style.css">
<link rel="StyleSheet" href="<%=webapp%>/menu/dtree.css" type="text/css" />
<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
var checkflag = "false"
function check(field) {
if (checkflag == "false") {
for (i = 1i <field.lengthi++) {
field[i].checked = true
field[i].disabled = true
}
checkflag = "true"
}else {
for (i = 1i <field.lengthi++) {
field[i].checked = false
field[i].disabled=false
}
checkflag = "false"
}
}
//------选中二级全选--------
var selectflag = "false"
function selectAll(field,j) {
if (selectflag == "false") {
for (i = 0i <field.lengthi++) {
var b ="ckb"+j
if(field[i].id==b){
field[i].checked = true
field[i].disabled=true
selectflag = "true"
}
}
}else {
for (i = 0i <field.lengthi++) {
var b ="ckb"+j
if(field[i].id==b||field[i].id==j){
field[i].checked = false
field[i].disabled = false
selectflag = "false"
}
}
}
}
//--------取消二级全选-------
function disabledAll(){
field = document.getElementById("myform")
for (i = 0i <field.lengthi++) {
if(field[i].checked == true){
field[i].disabled = true
checkflag = "false"
selectflag = "false"
}
}
}
//------取消选取--------
function cancelAll(field){
//field = myform.all
field = document.getElementById("myform")
for (i = 0i <field.lengthi++) {
field[i].checked = false
field[i].disabled=false
checkflag = "false"
selectflag = "false"
}
}
//单击提交页面
function onSubit(){
var txt = ""
//field = myform.all
field = document.getElementById("myform")
for (i = 0i <field.lengthi++) {
if(field[i].checked == true&&field[i].disabled==false){
txt += field[i].value+"."
}
}
//alert("=="+txt)
//取得父窗口对象
var winOpen=window.opener
winOpen.document.form.fundtype.value=txt
window.close()
}
// End -->
</script>
</head>
<body onLoad="disabledAll()">
<script type="text/javascript" src="<%=webapp%>/menu/dtree_2.js"></script>
<form name="myform" method="post" id="myform">
<table width="250" border="0" cellspacing="0" cellpadding="5">
<tr>
<td colspan="2"><table width="100%" border=0 cellpadding=0 cellspacing=0 bgcolor="#FFFFFF">
<tr>
<td>基金投资类型</td>
</tr>
<tr>
<td>
<div class="dtree">
<script type="text/javascript">
<!--//
d = new dTree('d')
${tree}
document.write(d)
//-->
</script>
</div>
</td>
</tr>
</table></td>
</tr>
<tr height="25" >
<td width="86" height="0"align="center"><a href="#" onClick="onSubit()"><img src="<%=webapp%>/img/btn_sure.gif" width="51" height="21" border="0"></a></td>
<td width="144" height="0"><a href="#" onClick="cancelAll()"><img src="<%=webapp%>/img/btn_cancel.gif" width="51" height="21" border="0"></a></td>
</tr>
</table>
</form>
</body>
</html>
3。js文件：
// Node object
function Node(id, pid, name, url, title, target, icon, iconOpen, open) {
this.id = id
this.pid = pid
this.name = name
this.url = url
this.title = title
this.target = target
this.icon = icon
this.iconOpen = iconOpen
this._io = open || false
this._is = false
this._ls = false
this._hc = false
this._ai = 0
this._p
}
// Tree object
function dTree(objName) {
this.config = {
target : null,
folderLinks : true,
useSelection : true,
useCookies : true,
useLines: true,
useIcons: true,
useStatusText : false,
closeSameLevel : false,
inOrder : false
}
this.icon = {
root: './fund/menu/img/base.gif',
folder : './fund/menu/img/folder.gif',
folderOpen : './fund/menu/img/folderopen.gif',
node: './fund/menu/img/page.gif',
empty: './fund/menu/img/empty.gif',
line: './fund/menu/img/line.gif',
join: './fund/menu/img/join.gif',
joinBottom : './fund/menu/img/joinbottom.gif',
plus: './fund/menu/img/plus.gif',
plusBottom : './fund/menu/img/plusbottom.gif',
minus: './fund/menu/img/minus.gif',
minusBottom : './fund/menu/img/minusbottom.gif',
nlPlus : './fund/menu/img/nolines_plus.gif',
nlMinus : './fund/menu/img/nolines_minus.gif'
}
this.obj = objName
this.aNodes = []
this.aIndent = []
this.root = new Node(-1)
this.selectedNode = null
this.selectedFound = false
this.completed = false
}
// Adds a new node to the node array
dTree.prototype.add = function(id, pid, name, url, title, target, icon, iconOpen, open) {
this.aNodes[this.aNodes.length] = new Node(id, pid, name, url, title, target, icon, iconOpen, open)
}
// Open/close all nodes
dTree.prototype.openAll = function() {
this.oAll(true)
}
dTree.prototype.closeAll = function() {
this.oAll(false)
}
// Outputs the tree to the page
dTree.prototype.toString = function() {
var str = '<div class="dtree">\n'
if (document.getElementById) {
if (this.config.useCookies) this.selectedNode = this.getSelected()
str += this.addNode(this.root)
} else str += 'Browser not supported.'
str += '</div>'
if (!this.selectedFound) this.selectedNode = null
this.completed = true
return str
}
// Creates the tree structure
dTree.prototype.addNode = function(pNode) {
var str = ''
var n=0
if (this.config.inOrder) n = pNode._ai
for (nn<this.aNodes.lengthn++) {
if (this.aNodes[n].pid == pNode.id) {
var cn = this.aNodes[n]
cn._p = pNode
cn._ai = n
this.setCS(cn)
if (!cn.target &&this.config.target) cn.target = this.config.target
if (cn._hc &&!cn._io &&this.config.useCookies) cn._io = this.isOpen(cn.id)
if (!this.config.folderLinks &&cn._hc) cn.url = null
if (this.config.useSelection &&cn.id == this.selectedNode &&!this.selectedFound) {
cn._is = true
this.selectedNode = n
this.selectedFound = true
}
str += this.node(cn, n)
if (cn._ls) break
}
}
return str
}
// Creates the node icon, url and text
dTree.prototype.node = function(node, nodeId) {
var str = '<div class="dTreeNode">' + this.indent(node, nodeId)
if (this.config.useIcons) {
if (!node.icon) node.icon = (this.root.id == node.pid) ? this.icon.root : ((node._hc) ? this.icon.folder : this.icon.node)
if (!node.iconOpen) node.iconOpen = (node._hc) ? this.icon.folderOpen : this.icon.node
if (this.root.id == node.pid) {
node.icon = this.icon.root
node.iconOpen = this.icon.root
}
str += '<img id="i' + this.obj + nodeId + '" src="' + ((node._io) ? node.iconOpen : node.icon) + '" alt="" />'
}
if (node.url) {
str += '<a id="s' + this.obj + nodeId + '" class="' + ((this.config.useSelection) ? ((node._is ? 'nodeSel' : 'node')) : 'node') + '" href="' + node.url + '"'
if (node.title) str += ' title="' + node.title + '"'
if (node.target) str += ' target="' + node.target + '"'
if (this.config.useStatusText) str += ' onmouseover="window.status=\'' + node.name + '\'return true" onmouseout="window.status=\'\'return true" '
if (this.config.useSelection &&((node._hc &&this.config.folderLinks) || !node._hc))
str += ' onclick="javascript: ' + this.obj + '.s(' + nodeId + ')"'
str += '>'
}
else if ((!this.config.folderLinks || !node.url) &&node._hc &&node.pid != this.root.id)
str += '<a href="javascript: ' + this.obj + '.o(' + nodeId + ')" class="node">'
str += node.name
if (node.url || ((!this.config.folderLinks || !node.url) &&node._hc)) str += '</a>'
str += '</div>'
if (node._hc) {
str += '<div id="d' + this.obj + nodeId + '" class="clip" style="display:' + ((this.root.id == node.pid || node._io) ? 'block' : 'none') + '">'
str += this.addNode(node)
str += '</div>'
}
this.aIndent.pop()
return str
}
// Adds the empty and line icons
dTree.prototype.indent = function(node, nodeId) {
var str = ''
if (this.root.id != node.pid) {
for (var n=0n<this.aIndent.lengthn++)
str += '<img src="' + ( (this.aIndent[n] == 1 &&this.config.useLines) ? this.icon.line : this.icon.empty ) + '" alt="" />'
(node._ls) ? this.aIndent.push(0) : this.aIndent.push(1)
if (node._hc) {
str += '<a href="javascript: ' + this.obj + '.o(' + nodeId + ')"><img id="j' + this.obj + nodeId + '" src="'
if (!this.config.useLines) str += (node._io) ? this.icon.nlMinus : this.icon.nlPlus
else str += ( (node._io) ? ((node._ls &&this.config.useLines) ? this.icon.minusBottom : this.icon.minus) : ((node._ls &&this.config.useLines) ? this.icon.plusBottom : this.icon.plus ) )
str += '" alt="" /></a>'
} else str += '<img src="' + ( (this.config.useLines) ? ((node._ls) ? this.icon.joinBottom : this.icon.join ) : this.icon.empty) + '" alt="" />'
}
return str
}
// Checks if a node has any children and if it is the last sibling
dTree.prototype.setCS = function(node) {
var lastId
for (var n=0n<this.aNodes.lengthn++) {
if (this.aNodes[n].pid == node.id) node._hc = true
if (this.aNodes[n].pid == node.pid) lastId = this.aNodes[n].id
}
if (lastId==node.id) node._ls = true
}
// Returns the selected node
dTree.prototype.getSelected = function() {
var sn = this.getCookie('cs' + this.obj)
return (sn) ? sn : null
}
// Highlights the selected node
dTree.prototype.s = function(id) {
if (!this.config.useSelection) return
var cn = this.aNodes[id]
if (cn._hc &&!this.config.folderLinks) return
if (this.selectedNode != id) {
if (this.selectedNode || this.selectedNode==0) {
eOld = document.getElementById("s" + this.obj + this.selectedNode)
eOld.className = "node"
}
eNew = document.getElementById("s" + this.obj + id)
eNew.className = "nodeSel"
this.selectedNode = id
if (this.config.useCookies) this.setCookie('cs' + this.obj, cn.id)
}
}
// Toggle Open or close
dTree.prototype.o = function(id) {
var cn = this.aNodes[id]
this.nodeStatus(!cn._io, id, cn._ls)
cn._io = !cn._io
if (this.config.closeSameLevel) this.closeLevel(cn)
if (this.config.useCookies) this.updateCookie()
}
// Open or close all nodes
dTree.prototype.oAll = function(status) {
for (var n=0n<this.aNodes.lengthn++) {
if (this.aNodes[n]._hc &&this.aNodes[n].pid != this.root.id) {
this.nodeStatus(status, n, this.aNodes[n]._ls)
this.aNodes[n]._io = status
}
}
if (this.config.useCookies) this.updateCookie()
}
// Opens the tree to a specific node
dTree.prototype.openTo = function(nId, bSelect, bFirst) {
if (!bFirst) {
for (var n=0n<this.aNodes.lengthn++) {
if (this.aNodes[n].id == nId) {
nId=n
break
}
}
}
var cn=this.aNodes[nId]
if (cn.pid==this.root.id || !cn._p) return
cn._io = true
cn._is = bSelect
if (this.completed &&cn._hc) this.nodeStatus(true, cn._ai, cn._ls)
if (this.completed &&bSelect) this.s(cn._ai)
else if (bSelect) this._sn=cn._ai
this.openTo(cn._p._ai, false, true)
}
// Closes all nodes on the same level as certain node
dTree.prototype.closeLevel = function(node) {
for (var n=0n<this.aNodes.lengthn++) {
if (this.aNodes[n].pid == node.pid &&this.aNodes[n].id != node.id &&this.aNodes[n]._hc) {
this.nodeStatus(false, n, this.aNodes[n]._ls)
this.aNodes[n]._io = false
this.closeAllChildren(this.aNodes[n])
}
}
}
// Closes all children of a node
dTree.prototype.closeAllChildren = function(node) {
for (var n=0n<this.aNodes.lengthn++) {
if (this.aNodes[n].pid == node.id &&this.aNodes[n]._hc) {
if (this.aNodes[n]._io) this.nodeStatus(false, n, this.aNodes[n]._ls)
this.aNodes[n]._io = false
this.closeAllChildren(this.aNodes[n])
}
}
}
// Change the status of a node(open or closed)
dTree.prototype.nodeStatus = function(status, id, bottom) {
eDiv = document.getElementById('d' + this.obj + id)
eJoin = document.getElementById('j' + this.obj + id)
if (this.config.useIcons) {
eIcon = document.getElementById('i' + this.obj + id)
eIcon.src = (status) ? this.aNodes[id].iconOpen : this.aNodes[id].icon
}
eJoin.src = (this.config.useLines)?
((status)?((bottom)?this.icon.minusBottom:this.icon.minus):((bottom)?this.icon.plusBottom:this.icon.plus)):
((status)?this.icon.nlMinus:this.icon.nlPlus)
eDiv.style.display = (status) ? 'block': 'none'
}
// [Cookie] Clears a cookie
dTree.prototype.clearCookie = function() {
var now = new Date()
var yesterday = new Date(now.getTime() - 1000 * 60 * 60 * 24)
this.setCookie('co'+this.obj, 'cookieValue', yesterday)
this.setCookie('cs'+this.obj, 'cookieValue', yesterday)
}
// [Cookie] Sets value in a cookie
dTree.prototype.setCookie = function(cookieName, cookieValue, expires, path, domain, secure) {
document.cookie =
escape(cookieName) + '=' + escape(cookieValue)
+ (expires ? 'expires=' + expires.toGMTString() : '')
+ (path ? 'path=' + path : '')
+ (domain ? 'domain=' + domain : '')
+ (secure ? 'secure' : '')
}
// [Cookie] Gets a value from a cookie
dTree.prototype.getCookie = function(cookieName) {
var cookieValue = ''
var posName = document.cookie.indexOf(escape(cookieName) + '=')
if (posName != -1) {
var posValue = posName + (escape(cookieName) + '=').length
var endPos = document.cookie.indexOf('', posValue)
if (endPos != -1) cookieValue = unescape(document.cookie.substring(posValue, endPos))
else cookieValue = unescape(document.cookie.substring(posValue))
}
return (cookieValue)
}
// [Cookie] Returns ids of open nodes as a string
dTree.prototype.updateCookie = function() {
var str = ''
for (var n=0n<this.aNodes.lengthn++) {
if (this.aNodes[n]._io &&this.aNodes[n].pid != this.root.id) {
if (str) str += '.'
str += this.aNodes[n].id
}
}
this.setCookie('co' + this.obj, str)
}
// [Cookie] Checks if a node id is in a cookie
dTree.prototype.isOpen = function(id) {
var aOpen = this.getCookie('co' + this.obj).split('.')
for (var n=0n<aOpen.lengthn++)
if (aOpen[n] == id) return true
return false
}
// If Push and pop is not implemented by the browser
if (!Array.prototype.push) {
Array.prototype.push = function array_push() {
for(var i=0i<arguments.lengthi++)
this[this.length]=arguments[i]
return this.length
}
}
if (!Array.prototype.pop) {
Array.prototype.pop = function array_pop() {
lastElement = this[this.length-1]
this.length = Math.max(this.length-1,0)
return lastElement
}
}
以WPS 2019版本为例：
关于excel表格怎样设置一级，二级，三级及多级下拉菜单，在WPS「表格（Excel）」中操作方法如下：
1、首先，我们在表格将数据分别录入到Sheet2和Sheet3中，Sheet2中是一级和二级，Sheet3中是二级和三级的数据。和之前制作二级下拉菜单的方式差不多，我们先进入Sheet2中，选择所有数据，点击「公式-指定-只保留「首行」前面的勾，其他的全部取消掉。同样的方法，我们再次进入Sheet3中进行操作；
2、设置一级下拉菜单：进入Sheet1，选中A2单元格，进入「数据-有效性-有效性-选择序列」，在「来源」中选择Sheet2中的「A1:C1」单元格（就是一级下拉菜单的内容）；
（注意：设置完成后续先选中一个选项，否则设置二级时会提示错误）
3、设置二级下拉菜单。光标定位到B2单元格，然后进入「数据-有效性-有效性-选择序列」「来源」中输入「=INDIRECT(A2)」确定；
4、设置三级下拉菜单。选中C2单元格，同样的操作，只是在「来源」中输入的是「=INDIRECT(B2)」。最后，我们选中A2:C2单元格，向下填充一下。此时，我们的多级下拉菜单就已经全部完成。
