????<div?id="divselect">
????????<cite>請(qǐng)選擇分類(lèi)</cite>
????????<ul>
????????????<li?id="li"><a?href="javascript:;"?selectid="1">ASP開(kāi)發(fā)</a></li>
????????????<li><a?href="javascript:;"?selectid="2">.NET開(kāi)發(fā)</a></li>
????????????<li><a?href="javascript:;"?selectid="3">PHP開(kāi)發(fā)</a></li>
????????????<li><a?href="javascript:;"?selectid="4">Javascript開(kāi)發(fā)</a></li>
????????????<li><a?href="javascript:;"?selectid="5">Java特效</a></li>
????????</ul>
????</div>
????
??????????var?box?=?document.getElementById('divselect'),
????????????title?=?box.getElementsByTagName('cite')[0],
????????????menu?=?box.getElementsByTagName('ul')[0],
????????????as?=?box.getElementsByTagName('a'),
????????????index?=?-1;
????????//?點(diǎn)擊三角時(shí)
????????title.onclick?=?function(event)?{
????????????//?執(zhí)行腳本
????????????event?=?event?||?window.event;
????????????menu.style.display?=?'block';
????????????if?(event?&&?event.stopPropagation)?{
???????????? event.stopPropagation();
????????????}else?{
???????????? event.cancelBuble?=?true;
????????????}
????????document.onkeyup?=?function?(event)?{
???????? console.log(event.keyCode);
???????? event?=?event?||?window.event;
???????? for?(var?i?=?0;?i?<?as.length;?i++)?{
???????? as[i].style.backgroundColor?=?"#fff";
???????? }
???????? if?(event.keyCode==38)?{
???????? index--;
???????? as[index].style.backgroundColor?=?"#eee";
???????? if?(index<0)?{
???????? index?=?as.length;
???????? }
???????? }else?if?(event.keyCode==40)?{
???????? index++;
???????? as[index].style.backgroundColor?=?"#eee";
???????? if?(index>as.length)?{
???????? index?=?0;
???????? }
???????? }
????????}
????????}if (index<0) {index = as.length;}和if (index>as.length) {index = 0;}都沒(méi)有被執(zhí)行，為什么？
為什么部分代碼不起作用？
UIll
2016-05-13 09:13:08
