1.创建Option对象
1.1 var optionEle1 = document.createElement('option');
1.2 var optionEle2 = new Option(text, value, defaultSelected, selected);
2.options属性
2.1 select.options返回select标签下面的Option对象的集合
3.清空下拉菜单
3.1 利用for循环删除,注意数组长度的动态变化
3.2 select.options.length = 0;
4.应用
<html> <head> <script language="javascript"> function number(){ var obj = document.getElementById("mySelect"); //obj.options[obj.selectedIndex] = new Option("我的吃吃","4");//在当前选中的那个的值中改变 //obj.options.add(new Option("我的吃吃","4"));再添加一个option //alert(obj.selectedIndex);//显示序号，option自己设置的 //obj.options[obj.selectedIndex].text = "我的吃吃";更改值 //obj.remove(obj.selectedIndex);删除功能 } </script> </head> <body> <select id="mySelect"> <option>我的包包</option> <option>我的本本</option> <option>我的油油</option> <option>我的担子</option> </select> <input type="button" name="button" value="查看结果"> </body> </html>
1.动态创建select
function createSelect(){ var mySelect = document.createElement("select"); mySelect.id = "mySelect"; document.body.appendChild(mySelect); }
2.添加选项option
function addOption(){ //根据id查找对象， var obj=document.getElementById('mySelect'); //添加一个选项 obj.add(new Option("文本","值")); //这个只能在IE中有效 obj.options.add(new Option("text","value")); //这个兼容IE与firefox }
3.删除所有选项option
function removeAll(){ var obj=document.getElementById('mySelect'); obj.options.length=0; }
4.删除一个选项option
function removeOne(){ var obj=document.getElementById('mySelect'); //index,要删除选项的序号，这里取当前选中选项的序号 var index=obj.selectedIndex; obj.options.remove(index); }
5.获得选项option的值
var obj=document.getElementById('mySelect'); var index=obj.selectedIndex; //序号，取当前选中选项的序号 var val = obj.options[index].value;
6.获得选项option的文本
var obj=document.getElementById('mySelect'); var index=obj.selectedIndex; //序号，取当前选中选项的序号 var val = obj.options[index].text;
7.修改选项option
var obj=document.getElementById('mySelect'); var index=obj.selectedIndex; //序号，取当前选中选项的序号 var val = obj.options[index]=new Option("新文本","新值");
8.删除select
function removeSelect(){ var mySelect = document.getElementById("mySelect"); mySelect.parentNode.removeChild(mySelect); }
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//ZH-CN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html"> <head> <script language=JavaScript> function $(id) { return document.getElementById(id) } function show() { var selectObj=$("area") var myOption=document.createElement("option") myOption.setAttribute("value","10") myOption.appendChild(document.createTextNode("上海")) var myOption1=document.createElement("option") myOption1.setAttribute("value","100") myOption1.appendChild(document.createTextNode("南京")) selectObj.appendChild(myOption) selectObj.appendChild(myOption1) } function choice() { var index=$("area").selectedIndex; var val=$("area").options[index].getAttribute("value") if(val==10) { var i=$("context").childNodes.length-1; var remobj=$("context").childNodes[i]; remobj.removeNode(true) var sh=document.createElement("select") sh.add(new Option("浦东新区","101")) sh.add(new Option("黄浦区","102")) sh.add(new Option("徐汇区","103")) sh.add(new Option("普陀区","104")) $("context").appendChild(sh) } if(val==100) { var i=$("context").childNodes.length-1; var remobj=$("context").childNodes[i]; remobj.removeNode(true) var nj=document.createElement("select") nj.add(new Option("玄武区","201")) nj.add(new Option("白下区","202")) nj.add(new Option("下关区","203")) nj.add(new Option("栖霞区","204")) $("context").appendChild(nj) } } function calc() { var x=$("context").childNodes.length-1; alert(x) } function remove() { var i=$("context").childNodes.length-1; var remobj=$("context").childNodes[i]; remobj.removeNode(true) } </script> <body> <div id="context"> <select id="area" on change="choice()"> </select> </div> <input type=button value="显示"> <input type=button value="计算结点"> <input type=button value="删除"> </body> </html>
以上所述就是本文的全部内容了，希望大家能够喜欢。