要有封装的思想，把一系列操作不重复的地方提取出来，作为参数传入，并且复杂动作分解成几个小的运动
多物体运动，变量不能公用，会造成资源抢夺 缓冲运动时，与目标距离不同，速度也变化，并且会有小数所以要速度判定
function(){
var aLi =document.getElementsByTagName("li");
for(var i = 0;i<aLi.length;i++){
aLi[i].timer = null;//多物体运动，变量不能公用，会因为造成资源抢夺
aLi[i].alpha = 30;
aLi[i].onmouseover = function(){
startMove(this,100);
}
aLi[i].onmouseout= function(){
startMove(this,30);
}
}
}
function startMove(obj,iTarget){
clearInterval(obj.timer);
var speed;
obj.timer = setInterval(function(){
speed = (iTarget-obj.alpha)/10;
//由目标和现值决定正负值,注意要取整，当距离小于10的时候，除了之后会是小数，这样会造成最后距离偏差
//凡是有变速运动都要有这个速度的判定
speed = speed > 0 ? Math.ceil(speed) : Math.floor(speed);
if(iTarget == obj.alpha){
clearInterval(obj.timer);
}else{
obj.alpha+=speed;
obj.style.filter = "alpha(opacity:"+obj.alpha+")";
obj.style.opacity = obj.alpha / 100;
}
},30)
}
定时器部分
timer = setInterval (function(){
var speed = 0;
if(oDiv.offsetLeft > iTarget ){
//如果当前offsetLeft 大于目标值，即0-->-200那么速度是负的
speed = -10;
}else{
//如果当前offsetLeft 小于目标值，即-200-->0那么速度是正的
speed = 10;
}
if(oDiv.offsetLeft == iTarget){
clearInterval(timer);
}else{
oDiv.style.left = oDiv.offsetLeft + speed+"px";
}
},20);
获取要变化的样式
function getStyle(obj,attr){ //解决offset样式属性的bug
if(obj.currentStyle){
return obj.currentStyle[attr];//IE获得其属性
}else {
return getComputedStyle(obj,false)[attr];//火狐获得其属性
}
}
//return 的是字符串，要转换成整型parseInt()
运动框架
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="Generator" content="EditPlus®">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
<title>链式动画</title>
<style>
*{
margin:0;
padding:0;
}
li {
width:200px;
height:100px;
margin-bottom:10px;
background-color:yellow;
border:2px solid blue;
opacity:0.3;
filter:alpha(opacity:30);/*IE环境*/
}
</style>
<script src="startMove.js"></script>
<script>
window.onload = function(){
var aLi =document.getElementById("li1");
//移入
aLi.onmouseover = function(){
startMove(aLi,'width',400,function(){
startMove(aLi,'height',200,function(){
//console.log(this);//此时是window调用
startMove(aLi,'opacity',100);
});
});
}
//移出
aLi.onmouseout = function(){
startMove(aLi,'opacity',30,function(){
startMove(aLi,'height',100,function(){
startMove(aLi,'width',200);
});
});
}
}
</script>
</head>
<body>
<ul>
<li id="li1"></li>
</ul>
</body>
</html>
function startMove(obj,attr,iTarget,fn){
//获取参数
clearInterval(obj.timer);
var speed,icurr;
obj.timer = setInterval(function(){
if(attr == 'opacity'){
icurr =Math.round(parseFloat(getStyle(obj,attr))*100);//透明度是小数,计算机的取值，用Math.round()四舍五入
}else{
icurr = parseInt(getStyle(obj,attr));//获取当前属性
}
//计算速度
//凡是有变速运动都要有这个速度的判定
//speed = (iTarget-obj.offsetWidth)/10;
speed = (iTarget - icurr)/10;
speed = speed > 0 ? Math.ceil(speed) : Math.floor(speed);
//判定动画结束
if( icurr == iTarget){
//if(iTarget == obj.offsetWidth){
clearInterval(obj.timer);
if(fn){
fn();
}
}else{
//动画过程
if(attr == 'opacity'){
obj.style.filter = "alpha(opacity:"+(icurr+speed)+")";//IE
obj.style.opacity = (icurr+speed)/100;//非IE
}else{
obj.style[attr] = icurr + speed +"px";
}
//obj.style.width = obj.offsetWidth + speed +"px";
}
},30)
}
//获取当前参数的属性值
function getStyle(obj,attr){ //解决offset样式属性的bug
if(obj.currentStyle){
return obj.currentStyle[attr];//IE获得其属性
}else {
return getComputedStyle(obj,false)[attr];//火狐获得其属性
}
}
同时发生动作 用到json键值对
<script>
window.onload = function(){
var aLi =document.getElementById("li1");
//移入
aLi.onmouseover = function(){
startMove(aLi,{width:201,height:200,opacity:100});
}
//移出
aLi.onmouseout = function(){
startMove(aLi,{width:200,height:100,opacity:30});
}
}
</script>
**move.js:**
//startMove(obj,{attr1:iTarget,attr2:iTarget},fn);
function startMove(obj,json,fn){
//1.获取参数
clearInterval(obj.timer);
var speed,icurr;
obj.timer = setInterval(function(){
var flag = true;
for(var attr in json){
if(attr == 'opacity'){
icurr =Math.round(parseFloat(getStyle(obj,attr))*100);//透明度是小数,计算机的取值，用Math.round()四舍五入
}else{
icurr = parseInt(getStyle(obj,attr));//获取当前属性
}
//2.计算速度
//凡是有变速运动都要有这个速度的判定
//speed = (iTarget-obj.offsetWidth)/10;
speed = (json[attr] - icurr)/10;
speed = speed > 0 ? Math.ceil(speed) : Math.floor(speed);
//3.判定动画是否全部执行结束
if( icurr != json[attr]){
flag = false;//不是，就赋值false
}
//动画过程
if(attr == 'opacity'){
obj.style.filter = "alpha(opacity:"+(icurr+speed)+")";//IE
obj.style.opacity = (icurr+speed)/100;//非IE
}else{
obj.style[attr] = icurr + speed +"px";
}
//obj.style.width = obj.offsetWidth + speed +"px";
}
if(flag){ //如果全部完成
clearInterval(obj.timer);
if(fn){
fn();
}
}
},30)
}
//获取当前参数的属性值
function getStyle(obj,attr){ //解决offset样式属性的bug
if(obj.currentStyle){
return obj.currentStyle[attr];//IE获得其属性
}else {
return getComputedStyle(obj,false)[attr];//火狐获得其属性
}
}
