為什么鼠標(biāo)移入一次才觸發(fā)一次而不是鏈?zhǔn)降模?/h1>
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>relative樣式</title>
<style type="text/css">
*{margin:0;padding:0}
ul,li{list-style:none}
ul li{width:200px;
????? height:100px;
????? background:yellow;
????? margin-bottom:20px;
?? border:2px solid #000;
?? filter:alpha(opacity:30);
?? opacity: 0.3;
????
?? }
</style>
<script type="text/javascript">
window.onload=function(){
?var Li=document.getElementById("li1");
?
?Li.onmouseover=function(){
??startMove(Li,{width:400},function(){
???startMove(Li,{height:200},function(){
????startMove(Li,{opacity:100});
???});
??});
?}
?
}
function getStyle(obj,attr){
??? if(obj.currentStyle){
??????? return obj.currentStyle[attr];
??? }
?else{
??????? return getComputedStyle(obj,false)[attr];
??? }
}
var alpha=30;
function startMove(obj,json,fn){
??var flag=true;
??clearInterval(obj.timer);
??obj.timer=setInterval(function(){
???for(var attr in json){
???var icur=0;
????if(attr=='opacity'){
?????icur=Math.round(parseFloat(getStyle(obj,attr))*100);
????}
????else{
?????icur=parseInt(getStyle(obj,attr));
????}
?
????var a=(json[attr]-icur)/8;
????a=a>0?Math.ceil(a):Math.floor(a);
????if(icur!==json[attr]){
?????flag=false;
????}
???
????if(attr=='opacity'){
?????obj.style.filter='alpha(opacity:'+(icur+a)+')';
?????obj.style.opacity=(icur+a)/100;
????}
????else{
?????obj.style[attr]=icur+a+'px';
????}
????if(flag){
?????clearInterval(obj.timer);
?????if(fn){
??????fn();
?????}
????}
?
???}
?
??},30)
?}
?
</script>
</head>
<body>
?<ul>
?<li id="li1"></li>
?
?
?</ul>
</body>
</html>
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>relative樣式</title>
<style type="text/css">
*{margin:0;padding:0}
ul,li{list-style:none}
ul li{width:200px;
????? height:100px;
????? background:yellow;
????? margin-bottom:20px;
?? border:2px solid #000;
?? filter:alpha(opacity:30);
?? opacity: 0.3;
????
?? }
</style>
<script type="text/javascript">
window.onload=function(){
?var Li=document.getElementById("li1");
?
?Li.onmouseover=function(){
??startMove(Li,{width:400},function(){
???startMove(Li,{height:200},function(){
????startMove(Li,{opacity:100});
???});
??});
?}
?
}
function getStyle(obj,attr){
??? if(obj.currentStyle){
??????? return obj.currentStyle[attr];
??? }
?else{
??????? return getComputedStyle(obj,false)[attr];
??? }
}
var alpha=30;
function startMove(obj,json,fn){
??var flag=true;
??clearInterval(obj.timer);
??obj.timer=setInterval(function(){
???for(var attr in json){
???var icur=0;
????if(attr=='opacity'){
?????icur=Math.round(parseFloat(getStyle(obj,attr))*100);
????}
????else{
?????icur=parseInt(getStyle(obj,attr));
????}
?
????var a=(json[attr]-icur)/8;
????a=a>0?Math.ceil(a):Math.floor(a);
????if(icur!==json[attr]){
?????flag=false;
????}
???
????if(attr=='opacity'){
?????obj.style.filter='alpha(opacity:'+(icur+a)+')';
?????obj.style.opacity=(icur+a)/100;
????}
????else{
?????obj.style[attr]=icur+a+'px';
????}
????if(flag){
?????clearInterval(obj.timer);
?????if(fn){
??????fn();
?????}
????}
?
???}
?
??},30)
?}
?
</script>
</head>
<body>
?<ul>
?<li id="li1"></li>
?
?
?</ul>
</body>
</html>
2016-07-04
解決方法：var flag = true;這句要放在定時(shí)器內(nèi)。
原因：如果放在外面，第一次運(yùn)行傳入定時(shí)器內(nèi)的flag值為true,第一遍檢測下列代碼時(shí)
????????if (icur != json[attr]){
???????? flag = false;
???????? }
返回的flag值為false，接下來30毫秒又重新執(zhí)行一遍定時(shí)器，flag的值還是為false，直到icur全都等于json[attr]時(shí)flag的值依舊不變，因此不會執(zhí)行停止定時(shí)器的代碼。換句話說，定時(shí)器在重復(fù)執(zhí)行speed為0的變化。