javascript操作多选下拉列表
闲来无事，把javascript操作多选下拉列表有关的操作知识复习了一遍，代码附上
<%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2014/8/9
Time: 18:05
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>多选下拉列表</title>
</head>
<body>
<div style="border:1px dashed #E6E6E6;margin:150px 0px 0px 450px; width:350px; height:200px; background-color:#E6E6E6;">
<table width="285" height="169" border="0" align="left" cellpadding="0" cellspacing="0"
style="margin:15px 0px 0px 15px;">
<tr>
<td width="126">
<!--multiple="multiple" 能同时选择多个 size="10" 确定下拉选的长度-->
<select name="first" multiple="multiple" size=10 class="td3" id="s">
<option value="选项1">选项1</option>
<option value="选项2">选项2</option>
<option value="选项3">选项3</option>
<option value="选项4">选项4</option>
<option value="选项5">选项5</option>
<option value="选项6">选项6</option>
<option value="选项7">选项7</option>
<option value="选项8">选项8</option>
</select>
</td>
<td width="69" valign="middle">
<input name="add" id="add" type="button" class="button" value="-->"/>
<input name="add_all" id="add_all" type="button" class="button" value="==>"/>
<input name="remove" id="remove" type="button" class="button" value="<--"/>
<input name="remove_all" id="remove_all" type="button" class="button" value="<=="/>
</td>
<td width="127" align="left">
<select name="second" size="10" multiple="multiple" class="td3" id="second">
<option value="选项9">选项9</option>
</select>
</td>
</tr>
</table>
</div>
</body>
<script language="JavaScript">
//dom结构绘制完毕，页面的所有关联文件必须加载完毕
window.onload = function () {
//选中的从左边移到右边
document.getElementById("add").onclick = function () {
//左侧
var firstElement = document.getElementById("first");
//右侧
var secondElement = document.getElementById("second");
//获取左侧option
var optionElements = firstElement.getElementsByTagName("option");
var len = optionElements.length;
/**
* firstElement.selectedIndex表示被选中的下标(从0开始)
* 如果未被选中，那么firstElement.selectedIndex=-1
*/
for (var i = 0; i < len; i++) {
if (firstElement.selectedIndex != -1) {
//从左边移到右边
secondElement.appendChild(optionElements[firstElement.selectedIndex]);
}
}
}
//单击左全选
document.getElementById("add_all").onclick = function () {
//左侧
var firstElement = document.getElementById("first");
//右侧
var secondElement = document.getElementById("second");
//获取左侧option
var optionElements = firstElement.getElementsByTagName("option");
var len = optionElements.length;
for (var i = 0; i < len; i++) {
//每次都是移动第一个到右边
secondElement.appendChild(optionElements[0]);
}
}
//双击左边移动到右边
document.getElementById("first").ondblclick = function () {
//左侧
var firstElement = document.getElementById("first");
//右侧
var secondElement = document.getElementById("second");
// //获取左侧option
// var optionElements = firstElement.getElementsByTagName("option");
// //双击的元素移到右边
// secondElement.appendChild(optionElements[firstElement.selectedIndex]);
//第二种方法
secondElement.appendChild(this[this.selectedIndex]);
}
//右边选中，移动到左边
document.getElementById("remove").onclick = function () {
//左侧
var firstElement = document.getElementById("first");
//右侧
var secondElement = document.getElementById("second");
//获取右侧option
var optionElements = secondElement.getElementsByTagName("option");
var len = optionElements.length;
for (var i = 0; i < len; i++) {
if (-1 != secondElement.selectedIndex) {
firstElement.appendChild(optionElements[secondElement.selectedIndex])
}
}
}
//单击右全选
document.getElementById("remove_all").onclick = function () {
//左侧
var firstElement = document.getElementById("first");
//右侧
var secondElement = document.getElementById("second");
//获取右侧option
var optionElements = secondElement.getElementsByTagName("option");
var len = optionElements.length;
for (var i = 0; i < len; i++) {
//每次都是移动第一个到右边
firstElement.appendChild(optionElements[0]);
}
}
//双击右侧，右侧元素移动到左侧
document.getElementById("second").ondblclick = function () {
//左侧
var firstElement = document.getElementById("first");
//右侧
var secondElement = document.getElementById("second");
//获取右侧option
var optionElements = secondElement.getElementsByTagName("option");
firstElement.appendChild(optionElements[secondElement.selectedIndex]);
}
}
</script>
</html>
