下面是页面中的一段html：
<div class="features">
<div class="container">
<div class="inner feature">
<div class="content">
<h2 class="title"><img src="./imgs/title1.png" alt=""/></h2>
<p class="text">256位SSL加密安全连接，手机短信验证、谷歌两步验证、资金密码、邮箱验证四重验证保障安全，钱包分布式离线冷存储</p>
</div>
<img class="icon" src="./imgs/feature-icon1.png" alt=""/>
</div>
</div>
<div class="container middle">
<div class="inner feature">
<div class="content">
<h2 class="title"><img src="./imgs/title1.png" alt=""/></h2>
<p class="text">256位SSL加密安全连接，手机短信验证、谷歌两步验证、资金密码、邮箱验证四重验证保障安全，钱包分布式离线冷存储</p>
</div>
<img class="icon" src="./imgs/feature-icon2.png" alt=""/>
</div>
</div>
<div class="container">
<div class="inner feature">
<div class="content">
<h2 class="title"><img src="./imgs/title1.png" alt=""/></h2>
<p class="text">256位SSL加密安全连接，手机短信验证、谷歌两步验证、资金密码、邮箱验证四重验证保障安全，钱包分布式离线冷存储</p>
</div>
<img class="icon" src="./imgs/feature-icon3.png" alt=""/>
</div>
</div>
</div>
首先，需要先定位图片，把图片定位在渐入后最终停留的位置:
.feature .icon { position: absolute top: 100px
}
接着，利用css3的transform属性和translate()方法实现图片的偏移，还有就是将图片透明度设为0(即完全透明)：
.feature .icon {position: absolute top: 100px transform: translate3d(0, 0, 150px) -ms-transform: translate3d(0, 150px, 0) -webkit-transform: translate3d(0, 150px, 0) -o-transform: translate3d(0, 150px, 0) -moz-transform: translate3d(0, 150px, 0) opacity: 0
}
这边需要加上各浏览器的前缀来兼容一些低版本浏览器。这些属性和方法的具体用法这边就细讲了。
然后，要用到的是css3的transition属性：
.feature .icon {position: absolute top: 100px transform: translate3d(0, 0, 150px) -ms-transform: translate3d(0, 150px, 0) -webkit-transform: translate3d(0, 150px, 0) -o-transform: translate3d(0, 150px, 0) -moz-transform: translate3d(0, 150px, 0) opacity: 0 transition: transform 1s ease 0s, opacity 1s ease 0s -moz-transition: -moz-transform 1s ease 0s, opacity 1s ease 0s -webkit-transition: -webkit-transform 1s ease 0s, opacity 1s ease 0s -o-transition: -o-transform 1s ease 0s, opacity 1s ease 0s -ms-transition: -ms-transform 1s ease 0s, opacity 1s ease 0s
}
transition属性是一个过渡属性，当元素从一种样式变换为另一种样式时为元素添加效果。
到这还没有效果。我们要达到的效果是：当网页往下滚动，图片出现或将要出现在视窗时，我们来触发这个过渡效果，就像大家看到的下面这张图片一样。这个做法就像图片的惰性加载，图片还没出现在视窗中时，先不加载，出现时再去加载图片，这样的效果就是用户访问页面的速度提升了。
把$("#testTable").mouseout改成$("#testTable").mouseleavemouseout在鼠标移入子元素时也会触发，而mouseleave只会在鼠标移出本元素时触发
以下是完整代码：
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE>New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<SCRIPT LANGUAGE="JavaScript" src="jquery.js"></SCRIPT>
<SCRIPT LANGUAGE="JavaScript">
//-----------------------------
var slowObj
var objWidth
var objHeight
var iter
var operator
var flag = true
function SlowDiv2(tableId,operator2){
slowObj = $("#"+tableId)
if(flag){
objWidth = slowObj.width()
objHeight = slowObj.height()
flag = false
}
slowObj.css({"overflow":"hidden"})
operator = operator2
if(operator=="show"){
slowObj.width(0)
slowObj.height(0)
}
iter = setInterval(operateTable,14)
}
function operateTable(){
var tmpWidth = slowObj.width()
var tmpHeight = slowObj.height()
if(operator=="hide"){
//隐藏table
if( (tmpWidth<=18 || tmpWidth-10<=0 ) &(tmpHeight<=18 || tmpHeight<=0)){
var d = clearInterval(iter)
slowObj.hide()
return
}else{
slowObj.width(tmpWidth-10)
slowObj.height(tmpHeight-10)
$("#ttest").val("-"+slowObj.width())
}
//$("#ttest").val(objWidth)
}else{
//显示table
slowObj.show()
if(tmpWidth+10>objWidth || tmpHeight+10>objHeight){
var d = clearInterval(iter)
slowObj.width(objWidth)
slowObj.height(objHeight)
return
}else{
slowObj.width(tmpWidth+20)
slowObj.height(tmpHeight+2)
$("#ttest").val("+"+slowObj.width())
}
// $("#ttest").val(objWidth)
}
}
$(document).ready(function(){
$("#S_switch").mouseover(function(){
SlowDiv2("testTable","show")
$("#S_switch").focus(function(){
$("#ttest").val("#S_switch")
})
}).mouseout(function(){
//alert("#S_switch out")
//SlowDiv2("testTable","show")
})
$("#testTable").mouseleave(function(){
// $("#ttest").val("table out")
SlowDiv2("testTable","hide")
}).mouseover(function(){
})
$("#testTable tr").mouseleave(function(){
//alert("tr out")
}).mouseover(function(){
//alert("tr over")
})
$("#testTable tr").css("background-color","pink")
})
</SCRIPT>
</HEAD>
<BODY>
<p id="S_switch" style="width:20pxbackground-color:grayfloat:lefttext-align:center">
<b>>></b>
</p>
<!-- div --->
<div style="width:302height:200pxbackground-color:pinkdisplay:none" id="testTable" >
<div style="background-color:#123abcwidth:100%">123213</div>
saf师大<br/>
1<br/>
1<br/>
</div>
</BODY>
</HTML>
