小编给大家分享一下JS中如何实现Select下拉列表类功能，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧！
具体代码如下所示：
<span > <HTML>
<HEAD>
<META http-equiv='Content-Type' content='text/html; charset=gb2312'>
<TITLE>可输入的下拉框</TITLE>
</HEAD>
<BODY >
<Script Language="Javascript">
var j = 0;
function SelectValue(obj)
{
var input = obj.parentNode.nextSibling;
document.all.box2.value = obj.options[obj.selectedIndex].text;
document.getElementById("txtSection").value=obj.options[obj.selectedIndex].value;
alert(document.getElementById("txtSection").value);
}
function InputValue(obj)
{
var n = 1;
var tmpObj;
var src = document.all.SelectOption;
var msg = document.all.msg;
if(event.keyCode != 40 && event.keyCode != 38 && event.keyCode != 13){
if(obj.value!=""){
msg.style.display="";
msg.innerHTML="";
if(msg.hasChildNodes())
{
msg.childNodes[0].parentNode.removeChild(msg.childNodes[0]);
}
for (var i=0;i<src.length;i++){
var selValue = document.createElement("div");
var selText = document.createElement("div");
selText.value = src(i).value;
selText.innerHTML = src(i).text;
if (src(i).text.toLowerCase().indexOf(obj.value.toLowerCase())==0){
selText.setAttribute("id","selText"+n);
selText.onmouseover=function (){
this.style.backgroundColor='#003399';
this.style.color ='#ffffff';
}
selText.onmouseout=function (){
this.style.backgroundColor='#ffffff';
this.style.color ='#000000';
}
selText.onclick=function (){
document.all.box2.value = this.innerHTML;
msg.style.display="none";
document.getElementById("txtSection").value=this.value;
}
msg.appendChild(selText);
n++;
}
}
}
else {
document.all.msg.style.display="none";
}
}
else {
//press down key
if(event.keyCode==40){
j++;
for (var i=0; i<src.length; i++)
{
tmpObj = document.getElementById("selText"+i);
if(tmpObj != null){
tmpObj.style.backgroundColor='#ffffff';
tmpObj.style.color ='#000000';
}
}
tmpObj = document.getElementById("selText"+j);
if(tmpObj != null){
tmpObj.style.backgroundColor='#003399';
tmpObj.style.color ='#ffffff';
}else{
j = 0;
}
}
//press up key
if (event.keyCode==38){
j--;
for (var i=0; i<src.length; i++)
{
tmpObj = document.getElementById("selText"+i);
if(tmpObj != null){
tmpObj.style.backgroundColor='#ffffff';
tmpObj.style.color ='#000000';
}
}
tmpObj = document.getElementById("selText"+j);
if(tmpObj != null){
tmpObj.style.backgroundColor='#003399';
tmpObj.style.color ='#ffffff';
}else{
j = 2;
}
}
//press enter key
if (event.keyCode==13){
tmpObj = document.getElementById("selText"+j);
document.all.box2.value = tmpObj.innerHTML;
msg.style.display="none";
document.getElementById("txtSection").value=tmpObj.value;
}
}
}
function SelMatch(src)
{
var currSel = document.all.box2.value;
for (var i=0;i<src.length;i++){
if (src(i).text==currSel)
{
src.options(i).selected = true;
}
}
}
function NoMsg()
{
if(document.activeElement.id=="msg")
return false;
else
document.all.msg.style.display='none';
}
</Script>
<TABLE border=0 cellPadding=1 cellSpacing=0 width="100%">
<TR>
<TD width="24%"><font face="Arial" size="2">Section</font></TD>
<TD COLSPAN=3 width="76%">
<div >
<span >
<select onchange="SelectValue(this)" onclick="SelMatch(this)" id="SelectOption" name="SelectOption" >
<OPTION value='ALL' Selected>ALL</OPTION>
<OPTION value='0TEST1'>0TEST1 = Testing 1
<OPTION value='0TEST1'>0TEST2 = Testing 1
<OPTION value='0TEST1'>0TEST3 = Testing 1
<OPTION value='SECTION'>SECTION = Section Description XXXXX AAA
</OPTION>
</select></span>
<input name="box2" id="box2" onkeyup="InputValue(this)" onblur="NoMsg()" onfocus="this.select();InputValue(this)" value="0" >
<div id="msg" style="border:1px solid green; font-size :14PX;white-space:nowrap;overflow:hidden;
width:230px;position:absolute;left:0px;top:20px;display:none"></div>
</div>
<Input Type="Hidden" Name="txtSection" id="txtSection">
</TD>
</TR>
</TABLE>
<p>
</BODY>
</HTML>
</span>以上是“JS中如何实现Select下拉列表类功能”这篇文章的所有内容，感谢各位的阅读！相信大家都有了一定的了解，希望分享的内容对大家有所帮助，如果还想学习更多知识，欢迎关注编程网行业资讯频道！
