請問為什么我的代碼這樣寫鼠標可以控制，可是鍵盤就控制不了呢？代碼錯在哪？怎么改
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>下拉菜單</title>
<style type="text/css">
body,
ul,
li {
margin: 0;
padding: 0;
font-size: 13px;
}
ul,
li {
list-style: none;
}
#divselect {
width: 186px;
margin: 80px auto;
position: relative;
z-index: 10000;
}
#divselect cite {
width: 150px;
height: 24px;
line-height: 24px;
display: block;
color: #807a62;
cursor: pointer;
font-style: normal;
padding-left: 4px;
padding-right: 30px;
border: 1px solid #333333;
background: url(xjt.png) no-repeat right center;
}
#divselect ul {
width: 184px;
border: 1px solid #333333;
background-color: #ffffff;
position: absolute;
z-index: 20000;
margin-top: -1px;
display: none;
}
#divselect ul li {
height: 24px;
line-height: 24px;
}
#divselect ul li a {
display: block;
height: 24px;
color: #333333;
text-decoration: none;
padding-left: 10px;
padding-right: 10px;
}
</style>
<script type="text/javascript">
window.onload = function() {
var box = document.getElementById('divselect'),
title = box.getElementsByTagName('cite')[0],
menu = box.getElementsByTagName('ul')[0],
as = box.getElementsByTagName('a'),
index = -1,
btn = false;
// 點擊三角時
title.onclick = function(event) {
event = event || window.event;
if(event.stopPropagation) {
event.stopPropagation();
} else {
event.cancelBubble();
}
if(btn == false) {
menu.style.display = "block";
btn = true;
} else {
menu.style.display = "none";
btn = false;
}
// 鍵盤事件
document.onkeyup = function(event) {
e = event || window.event;
if(e.keyCode == 40) {
index++;
if(index >= as.length) {
index = 0;
}
changebgd();
}
if(e.keyCode == 38) {
if(index <= 0) {
index = as.length;
}
index--;
changebgd();
}
}
}
// 鼠標滑過、離開、點擊每個選項時
for(var i = 0; i < as.length; i++) {
as[i].index = i;//得這樣傳值否則匿名函數(shù)獲取不到i的值
as[i].onmouseover = function() {
for(var j = 0; j < as.length; j++) {
as[j].style.background = "none";
}
this.style.background = "#ccc";
index = this.index;
keyenter();
}
// ? as[i].onmouseout=function(){
// ? ? ? this.style.background="#fff";
// ? }上面那樣寫、鍵盤上下移動后鼠標移動，LI不存在兩個“被選”。
as[i].onclick = function() {
title.innerHTML = this.innerHTML;
reset();
}
// 執(zhí)行腳本
}
// 執(zhí)行腳本
function changebgd() {
for(var i = 0; i < as.length; i++) {
as[i].style.background = "none";
}
as[index].style.background = "#ccc";
keyenter();
}
function keyenter() {
document.onkeyup = function(event) {
event = event || window.event;
if(event.keyCode == 13 && index != -1) {
title.innerHTML = as[index].innerHTML;
reset();
document.onkeyup=null;
}
}
}
// 點擊頁面空白處時
document.onclick = function() {
reset();
}
//復位函數(shù)
function reset() {
if(btn == true) {
if(index != -1) {
as[index].style.background = "none";
index = -1;
}
menu.style.display = "none";
btn = false;
}
}
// 執(zhí)行腳本
}
</script>
</head>
<body>
<div id="divselect">
<cite>請選擇分類</cite>
<ul>
<li id="li">
<a href="javascript:;" selectid="1">ASP開發(fā)</a>
</li>
<li>
<a href="javascript:;" selectid="2">.NET開發(fā)</a>
</li>
<li>
<a href="javascript:;" selectid="3">PHP開發(fā)</a>
</li>
<li>
<a href="javascript:;" selectid="4">Javascript開發(fā)</a>
</li>
<li>
<a href="javascript:;" selectid="5">Java特效</a>
</li>
</ul>
</div>
</body>
</html>
如果改，怎么個改法最好最少呢
2016-09-22
設置index值就是為了鼠標和鍵盤可以共同利用這個值控制選中項，每次鼠標經過或上下鍵按動時index值都在刷新，所以沒必要到處調用keyenter()函數(shù)，只需要判斷按鍵的鍵值的三種情況進行處理或者調用處理函數(shù)，你調用函數(shù)，各種嵌套，函數(shù)內又觸發(fā)事件，反而有點亂了。
還有個小問題，如果點開下拉列表，不選選項的話點空白處，選項隱藏不了，因為不選選項的話index值為-1，reset()函數(shù)第一句話走不通。建議：
1、將判斷鍵值的三種情況寫到一起，document.onkeyup=function(){} 里面；
2、將keyenter()中只留處理的兩行代碼；
3、去掉鼠標劃過和函數(shù)changeBgd()中的keyenter()函數(shù)調用；
4、在判斷回車鍵條件中調用keyenter()函數(shù)；
5、將reset()函數(shù)第一句話改為遍歷列表全部設置背景色；
<!doctype?html> <html> <head> ????<meta?charset="UTF-8"> ????<title>下拉菜單</title> ????<style?type="text/css"> body,ul,li{?margin:0;?padding:0;?font-size:13px;} ul,li{list-style:none;} #divselect{width:186px;?margin:80px?auto;?position:relative;?z-index:10000;} #divselect?cite{width:150px;?height:24px;line-height:24px;?display:block;?color:#807a62;?cursor:pointer;font-style:normal; padding-left:4px;?padding-right:30px;?border:1px?solid?#333333;? background:url(xjt.png)?no-repeat?right?center;} #divselect?ul{width:184px;border:1px?solid?#333333;?background-color:#ffffff;?position:absolute;?z-index:20000;?margin-top:-1px;?display:none;} #divselect?ul?li{height:24px;?line-height:24px;} #divselect?ul?li?a{display:block;?height:24px;?color:#333333;?text-decoration:none;?padding-left:10px;?padding-right:10px;} ????</style> ???<script?type="text/javascript"> window.onload=function(){ ????var?box=document.getElementById('divselect'), ????????title=box.getElementsByTagName('cite')[0], ????????menu=box.getElementsByTagName('ul')[0], ????????as=box.getElementsByTagName('a'), ????????index=-1, ????????btn=false; ????//?點擊三角時 ????title.onclick=function(event){ ????????event=event||window.event; ????????if(event.stopPropagation){ ????????????event.stopPropagation(); ????????}else{ ????????????event.cancelBubble(); ????????} ????????if(btn==false){ ???????????menu.style.display="block"; ???????????btn=true; ???????}else?{ ???????????menu.style.display="none"; ???????????btn=false; ???????} ??????? ???} ????//?鼠標滑過、離開、點擊每個選項時 ???for(var?i=0;i<as.length;i++){ ???????as[i].index=i; ???????as[i].onmouseover=function(){ ???????????for(var?j=0;j<as.length;j++){ ???????????????as[j].style.background="#fff"; ???????????} ???????????this.style.background="#ccc"; ???????????index=this.index; ???????????//keyenter(); ???????} ????//???as[i].onmouseout=function(){ ????//???????this.style.background="#fff"; ????//???}上面那樣寫、鍵盤上下移動后鼠標移動，LI不存在兩個“被選”。 ???????as[i].onclick=function(){ ???????????title.innerHTML=this.innerHTML; ???????????reset(); ???????} ??????//?執(zhí)行腳本 }?? ???//?鍵盤事件 ???document.onkeyup=function(event){ ???????event=event||window.event; ???????if(event.keyCode==40){ ???????????index++; ???????????if(index>=as.length){ ???????????????index=0; ???????????} ???????????changeBgd(); ???????} ???????if(event.keyCode==38){ ???????????if(index<=0){ ???????????????index=as.length; ???????????} ???????????index--; ???????????changeBgd(); ???????} ???????if(event.keyCode==13){ ???????????keyenter(); ???????} ???} ??????//?執(zhí)行腳本 ???function?keyenter(){ ????????title.innerHTML=as[index].innerHTML; ????????reset(); ??????? ???} ???function?changeBgd(){ ???????//alert("1"); ???????for(var?i=0;i<as.length;i++){ ???????????as[i].style.background="none"; ???????} ???????as[index].style.background="#ccc"; ???????//keyenter(); ???} ???//?點擊頁面空白處時 ???document.onclick=function(){ ???????reset(); ???} ???//復位函數(shù) ???function?reset(){ ???????for(var?i=0;i<as.length;i++){ ??????????as[i].style.background="none"; ???????} ??????????index=-1; ??????????menu.style.display="none"; ??????????btn=false;? ???}? ?} ???</script> </head> <body> ????<div?id="divselect"> ??????<cite>請選擇分類</cite> ??????<ul> ?????????<li?id="li"><a?href="javascript:;"?selectid="1">ASP開發(fā)</a></li> ?????????<li><a?href="javascript:;"?selectid="2">.NET開發(fā)</a></li> ?????????<li><a?href="javascript:;"?selectid="3">PHP開發(fā)</a></li> ?????????<li><a?href="javascript:;"?selectid="4">Javascript開發(fā)</a></li> ?????????<li><a?href="javascript:;"?selectid="5">Java特效</a></li> ??????</ul> ????</div> </body> </html>2016-12-07
求教一下，你的“//?鼠標滑過、離開、點擊每個選項時”這段代碼中，這個as[i].index=i;是什么意思？？
2016-09-22
建議你下載源碼看下吧，封裝函數(shù)有問題，各種函數(shù)嵌套反而更亂了