要求：
1. 点击input框显示下拉列表。
2. 选中下拉列表值后关闭列表。
3. 方向键可选列表中的项。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8"/>
<title>模拟搜索结果项 - 豪情</title>
<style type="text/css">
*{ margin:0; padding:0;}
body{font:12px/1.125 Arial,Helvetica,sans-serif;background:#fff;}
table{border-collapse:collapse;border-spacing:0;}
li{list-style:none;}
fieldset,img{border:0;}
article,aside,details,figcaption,figure,footer,header,hgroup,menu,nav,section{display:block}
q:before,q:after{content:'';}
a:focus,input,textarea{outline-style:none;}
input[type="text"],input[type="password"],textarea{outline-style:none;-webkit-appearance:none;}
textarea{resize:none}
address,caption,cite,code,dfn,em,i,th,var{font-style:normal;font-weight:normal;}
legend{color:#000;}
abbr,acronym{border:0;font-variant:normal;}
a{color:#333;text-decoration:none;}
a:hover{text-decoration:underline;}
.clearfix:after{content:".";display:block;height:0;clear:both;visibility:hidden;}
.clearfix{display:inline-block;}
.clearfix{display:block;}
.clear{clear:both;height:0;font:0/0 Arial;visibility:hidden;}
.none{display:none}
.demo{ width:550px;margin:50px auto;}
.input{width:543px; height:30px; line-height:30px; padding:3px 0 3px 5px; border:1px solid #ccc;background:#fff;}
.demo .hover{ display:block;}
.list{ border:1px solid #817f82;background:#fff; display:none;}
.list li{width:548px; text-indent:1em;display:block; height:28px; line-height:28px;}
.list li.cur{background:#ebebeb; text-decoration:none;}
</style>
</head>
<body>
<div class="demo">
<input class="input" type="text" name="" id="input" />
<ul id="list" class="list">
<li>豪情</li>
<li>sina</li>
<li>网易邮箱</li>
<li>新浪微博</li>
<li>腾讯微信</li>
</ul>
</div>
<script type="text/javascript">
function id(){
return document.getElementById(arguments[0]);
}
(function(window){
var input = id('input'),
list = id('list'),
oA = list.getElementsByTagName('li');
// show list
input.onclick = function(){
var items = null;
list.className = 'list hover';
// set first current css
for(var i = 0; i < oA.length; i++){
items = oA[i];
if(input.value && items.innerHTML == input.value){
items.className = 'cur';
}
}
}
// set first input val
input.value = oA[0].innerHTML;
// hide list
document.documentElement.onclick = function(e){
e = e ? e.target : window.event.srcElement;
if(e.tagName.toLowerCase() == 'body' || e.tagName.toLowerCase() == 'html'){
list.className = 'list';
}
}
var oLi = null;
for(var i = 0; i < oA.length; i++){
oLi = oA[i];
// click hide list and set input val
oLi.onclick = function(){
list.className = 'list';
input.value = this.innerHTML;
}
oLi.onmouseover = function(){
// clear all selected css
for(var j = 0; j < oA.length; j++){
oA[j].className = '';
}
this.className = 'cur';
}
oLi.onmouseout = function(){
this.className = '';
}
}
// keyboard trigger
document.documentElement.onkeydown = function(e){
e = e || window.event;
var target = e.target || e.srcElement,
kcode = 0,
index = getItems() || 0;
if(target.tagName.toLowerCase() == 'input' && list.className == 'list hover'){
kcode = e.keyCode;
switch(kcode){
case 13 : // enter
list.className = 'list';
break;
case 37 : // left
case 38 : // up
/*
if(index > 0){ // if min
hover(oA[index - 1]);
} else {
hover(oA[oA.length - 1]);
}
*/
hover(oA[index > 0 ? index - 1 : oA.length - 1]);
break;
case 39 : // right
case 40 : // down
/*
if(index < oA.length - 1){ // if max
hover(oA[index + 1]);
} else {
hover(oA[0]);
}
*/
hover(oA[index > 0 ? index + 1 : 0]);
break;
}
}
}
// get current index
function getItems(){
for(var i = 0; i < oA.length; i++){
if(oA[i].className == 'cur'){
return i;
}
}
}
// set hover class
function hover(obj){
for(var i = 0; i < oA.length; i++){
oA[i].className = '';
}
obj.className = 'cur';
input.value = obj.innerHTML;
}
}(window));
</script>
</body>
</html>
运行代码
