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Summary of various usages of select in html (code)

不言
不言Original
2018-08-09 14:28:096582browse

This article introduces to you a summary (code) of various usages of select in HTML. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

1) Hide and show select:

     $("selectList").style.display=$("selectList").style.display=="block"?"none":"block";

2) Select is available or unavailable:

       <select disabled="value">
      document.getElementById("LevelDropList").disabled = "value";      不可用
      document.getElementById("LevelDropList").disabled = "value";     可用
<html>
< head>
< SCRIPT LANGUAGE="JavaScript">
< !--
//oSelect 列表的底部添加了一个新选项
function onload(){
var oOption = document.createElement("OPTION");
oOption.text="Ferrari";
oOption.value="4";
oSelect.add(oOption);
}
function fnChange(){
oData.value+=oCars.options[oCars.selectedIndex].text + " ";
}


//-->
< /SCRIPT>
< /head>
<body onload="onload()">< !--手工添加一个Select-->
< !--1 uses the SELECT element to create a drop-down list box-->
<SELECT NAME="Cats" SIZE="1">
< OPTION VALUE="1">Calico
< OPTION VALUE="2">Tortie
< OPTION VALUE="3" SELECTED>Siamese
< /SELECT>
<P>
< !--2 select 元素创建了多项选择列表框,方法是设置了 SIZE 和 MULTIPLE 标签属性。要获得多项选择列表框的选中选项,则须遍历 options 集合并检查 SELECTED 是否被设为 true。-->
<SELECT ID="oSelect" NAME="Cars" SIZE="3" MULTIPLE> <!--此处设置了3和multiple-->
<OPTION VALUE="1" SELECTED>BMW
< OPTION VALUE="2">Porsche
< OPTION VALUE="3" SELECTED>Mercedes
< /SELECT>
<P>
< !--3 以下演示Option的用法-->
<SELECT ID="oCars" SIZE="1" onchange="fnChange()">
< OPTION VALUE="1">宝马
<OPTION VALUE="2">保时捷
<OPTION VALUE="3" SELECTED>大奔
< /SELECT>
<P>
< TEXTAREA ID="oData"></TEXTAREA>

< /body>
</html>

Attachment: Some Select skills

1. Dynamic Create select

function createSelect(){
var mySelect = document.createElement("select");
mySelect.id = "mySelect"; 
document.body.appendChild(mySelect);
}

2. Add option option

function addOption(){
//根据id查找对象,var obj=document.getElementById(&#39;mySelect&#39;);
//添加一个选项obj.add(new Option("文本","值"));}

3. Delete all options option

function removeAll(){
var obj=document.getElementById(&#39;mySelect&#39;);
obj.options.length=0;
}

4. Delete one option option

function removeOne(){
var obj=document.getElementById(&#39;mySelect&#39;);
//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. Get The value of option option

var obj=document.getElementById(&#39;mySelect&#39;);
var index=obj.selectedIndex; //序号,取当前选中选项的序号
var val = obj.options[index].value;

6. Get the text of option option

var obj=document.getElementById(&#39;mySelect&#39;);
var index=obj.selectedIndex; //序号,取当前选中选项的序号
var val = obj.options[index].text;

7. Modify option option

var obj=document.getElementById(&#39;mySelect&#39;);
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. Delete select

function removeSelect(){
var mySelect = document.getElementById("mySelect");
mySelect.parentNode.removeChild(mySelect);
}

9. Set select optin

function removeSelect(){
// 向办件人员下拉列表动态添加员工
for ( var i = 0; i < json.length; i++) {
var newOption = new Option(json[i].empname, json[i].empid, i);
//向办件人员下拉列表添加员工信息
objDeal.options.add(newOption);
//客户业务员的Id不为空
if(empbyDealEmpId!="" || empbyDealEmpId!=0){
//员工id等于下拉列表中的值,则下拉列表被选中
if(empbyDealEmpId==objDeal.options[i].value){
//判断此下拉列表被选中
objDeal.options[i].selected=true;

Recommended related articles:

How the HTML Select object operates the Option object

Introduction to three methods of distributing status across components in React

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