效果展示：
頁面初加載時： 
選擇車類型後： 
選擇車顏色後： 
JS實現下拉框的動態添加，網頁代碼如下：
復制代碼 代碼如下:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>動態添加下拉框</title>
<script type="text/javascript" src="../JS文件/jquery.js"></script>
<script type="text/javascript" src="../JS文件/SelectMenu2.js" charset=“utf-8”></script>
</head>
<body>
<form action="#">
<br />
<br />
<br />
<div class="CarInfo">
<span class="CarType">車類型：
<select >
<option value="請選擇" selected="selected">請選擇</option>
<option value="寶馬">寶馬</option>
<option value="奔馳">奔馳</option>
</select>
</span>
<span class="CarColor" style="display:none">車顏色：
<select>
</select>
</span>
<span class="CarWheel" style="display:none">車輪：
<select>
</select>
</span>
</div>
</form>
</body>
</html></SPAN>
JS代碼如下：
復制代碼 代碼如下:
// JavaScript Document
$(document).ready(function (){
var CarTypeSelect = $(".CarType").children("select");
var CarColorSelect = $(".CarColor").children("select");
var CarWheelSelect = $(".CarWheel").children("select");
//給第一個下拉框的SelectChanged時間編碼
CarTypeSelect.change(function (){
//取得當前下拉框的值
var CarTypeValue = $(this).val();
//當第一個下拉框內容改變的時候，第三個下拉框要隱藏起來
CarWheelSelect.parent().hide();
if(CarTypeValue !="")
{
CarColorSelect.html("");
$("<option value = ''>請選擇</option>").appendTo(CarColorSelect);
switch(CarTypeValue){
case "寶馬":
var CarColor=["綠色","黑色"];
for(var i = 0;i<CarColor.length;i++){
$("<option value='"+CarColor[i]+"'>" + CarColor[i] + "</option>").appendTo(CarColorSelect);
}
break;
case "奔馳":
var CarColor = ["白色","紅色"];
for(var i = 0;i<CarColor.length;i++){
$("<option value='"+CarColor[i]+"'>" + CarColor[i] + "</option>").appendTo(CarColorSelect);
}
break;
}
CarColorSelect.parent().show();
}
else
{
CarColorSelect.parent().hide();
}
});
CarColorSelect.change(function (){
var CarColorValue = $(this).val();
CarWheelSelect.html("");
if(CarColorValue != "")
{
CarWheelSelect.html("");
$("<option value = ''>請選擇</option>").appendTo(CarWheelSelect);
switch(CarColorValue){
case "綠色":
var CarWheel = ["綠鋼","綠碳纖維"];
for(var i = 0;i<CarWheel.length;i++){
$("<option value='"+CarWheel[i]+"'>" + CarWheel[i] + "</option>").appendTo(CarWheelSelect);
}
break;
case "紅色":
var CarWheel = ["紅鋼","紅碳纖維"];
for(var i = 0;i<CarWheel.length;i++){
$("<option value='"+CarWheel[i]+"'>" + CarWheel[i] + "</option>").appendTo(CarWheelSelect);
}
break;
case "黑色":
var CarWheel = ["黑鋼","黑碳纖維"];
for(var i = 0;i<CarWheel.length;i++){
$("<option value='"+CarWheel[i]+"'>" + CarWheel[i] + "</option>").appendTo(CarWheelSelect);
}
break;
case "白色":
var CarWheel = ["白鋼","白碳纖維"];
for(var i=0;i<CarWheel.length;i++){
$("<option vaiue='"+CarWheel[i]+"'>" + CarWheel[i] + "</option>").appendTo(CarWheelSelect);
}
break;
}
CarWheelSelect.parent().show();
}
else
{
CarWheelSelect.parent().hide();
}
});
});