Javascript操作Select和Option

rickycm · 发表于 2013-2-7 20:31:29

注意:Option中的O是要大写的，不然语法报错

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    }

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Option里面的四个参数分别的意思

new Option (text,value,defaultselected,selected)
new Option (文本,值,默认选中的选项,选中的选项)

看测试结果就懂了
  <select id="s1"></select>

  <script>
   var op = new Option("显示文本1","值1",false,false);
   s1.options.add(op);
   op =    new Option("显示文本2","值2",false,true);
   s1.options.add(op);
  </script>
-----------------------------------------------------------------

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);    }

整个实例的完整代码如下：

<!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" onchange="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>

改进版：在select中添加、修改、删除option元素

function watch_ini(){ // 初始for(var i=0; i<arguments.length; i++){var word = document.createElement("OPTION");word.text = arguments[i];watch.keywords.add(word); // watch. is form name}}function watch_add(f){ // 增加var word = document.createElement("OPTION");word.text = f.word.value;f.keywords.add(word);}
但上述 add() 方法只在IE下有效，为兼容FF和Opera，对上述代码进行了一下改进，改动后代码如下： function watch_ini(){ // 初始
for(var i=0; i<arguments.length; i++){ var oOption=new Option(arguments[i],arguments[i]); document.getElementById("MySelect")[i]=oOption;}}function watch_add(f){ // 增加 var oOption=new Option(f.word.value,f.word.value); f.keywords[f.keywords.length]=oOption;}

整个实例的完整代码如下：

<!doctype html public "-//w3c//dtd html 4.0 transitional//en"><html><head><title>javascript select options text value</title><meta name="keywords" content="javascript select options text value add modify delete set"><meta name="description" content="javascript select options text value add modify delete set"><script language="javascript"></script></head><body><form name="watch" method="post" action=""><select id="MySelect" name="keywords" size="10" onchange="watch_sel(this.form)"></select><br><script language="javascript"></script><input type="text" name="word" /><br /><input type="button" value="增加"  /><input type="button" value="修改"  /><input type="button" value="删除"  /><input type="button" value="保存"  /></form></body></html>

From:

http://hi.baidu.com/xiaowawa125/blog/item/d85d6539f9db42f43b87ce16.html

http://blog.ifeng.com/article/1828286.html

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Javascript操作Select和Option

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