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JS动态操作select下拉框

2012-08-04 15:12 344 查看

1.动态创建select

      function createSelect(){

var createSelect = document.createElement("select");//定义一个下拉框

          createSelect.id = "mySelect";//设置下拉框的ID

          document.body.appendChild(createSelect);//把定义的下拉框添加到页面中

      }

2.添加选项option

     function addOption(){

           var obj=document.getElementById('mySelect');//根据id查找对象，

         var addOption=new Option("文本","值");//生成一个选项

         obj.add(addOption);    //这个只能在IE中有效

         obj.options.add(addOption); //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');

var index =obj.selectedIndex;

obj.options.remove(index);

}

5.获得选项option的文本和值

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;//获取值
var val = obj.options[index].text;;//获取文本

6.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

obj.options[index]=new option("新文本","新值");

7.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" onclick="show()">

<input type=button value="计算结点" onclick="calc()">

<input type=button value="删除" onclick="remove()">

</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" onclick="watch_add(this.form);" />

<input type="button" value="修改" onclick="watch_mod(this.form);" />

<input type="button" value="删除" onclick="watch_del(this.form);" />

<input type="button" value="保存" onclick="watch_set(this.form);" />

</form>

用一个字符串创建一个数组方法:

<script language="javascript">

</body>

</html> <script>functionspli(){datastr="2,2,3,5,6,6";      varstr=newArray();       str=datastr.split(",");          for(i=0;i<str.length ;i++ )        {document.write(str[i]+"<br/>");  }   }
  spli();   </script>   -- 来源于互联网http://apps.hi.baidu.com/share/detail/31091794

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标签： function javascript button html delete ini

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