window封装类

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1.获取屏幕宽度的函数

2.获取屏幕高度的函数

3.获取滚动条横向宽度

4.获取滚动条竖向高度

5.window.onscroll绑定事件

6.删除window.onscroll绑定事件

7.window.onload绑定事件

8.让元素显示在屏幕中间

9.获取屏幕中间显示距离顶部的高度

10.固顶元素在屏幕中显示,不随滚动条的变化而变化


if(!coos)var coos = function(){};
if(!coos.browser)
{
coos.userAgent = navigator.userAgent.toLowerCase();
coos.browser = {
version: (coos.userAgent.match( /.+(?:rv|it|ra|ie)[\/: ]([\d.]+)/ ) || [0,'0'])[1],
safari: /webkit/.test(coos.userAgent),
opera: /opera/.test(coos.userAgent),
msie: /msie/.test(coos.userAgent) && !/opera/.test(coos.userAgent),
mozilla: /mozilla/.test(coos.userAgent) && !/(compatible|webkit)/.test(coos.userAgent)
};
}
coos.window = function(){};
coos.window.winWidth = 0;
coos.window.winHeight = 0;

/**
* 获取屏幕宽度的函数,在非xhtml标准页面下有可能有问题
*/
coos.window.width = function()
{
if (window.innerWidth)//for Firefox
{
coos.window.winWidth = window.innerWidth;
}
else if((document.body) && (document.body.clientWidth))
{
coos.window.winWidth = document.body.clientWidth;
}

if (document.documentElement && document.documentElement.clientWidth)
{
coos.window.winWidth = document.documentElement.clientWidth;
}
return coos.window.winWidth;
};

/**
* 获取屏幕高度的函数
* html,body高度属性必须设值为height:100%否则在火狐浏览器下获取不到真实高度
*/
coos.window.height = function()
{
if (window.innerHeight)//for Firefox
{
coos.window.winHeight = window.innerHeight;
}
else if((document.body) && (document.body.clientHeight))
{
coos.window.winHeight = document.body.clientHeight;
}

if (document.documentElement && document.documentElement.clientHeight)
{
coos.window.winHeight = document.documentElement.clientHeight;
}
return coos.window.winHeight;
};

/**
* 获取滚动条横向宽度
*/
coos.window.scrollWidth = function()
{
return document.body.scrollWidth + "px";
};

/**
* 获取滚动条竖向高度,取body.scrollHeight和documentElement.scrollHeight中最高的一个
*/
coos.window.scrollHeight = function()
{
return Math.max(document.body.scrollHeight,document.documentElement.scrollHeight) + "px";
};

coos.window.onscroll = function(){};

/**
* window.onscroll绑定事件
* @param fn 需要绑定的function
*/
coos.window.onscroll.add = function(fn)
{
if (window.addEventListener)
{
window.addEventListener("scroll",fn,false);
}
else
{
window.attachEvent("onscroll", fn);
}
};

/**
* 删除window.onscroll绑定事件
* @param fn 需要绑定的function
*/
coos.window.onscroll.remove = function(fn)
{
if (window.removeEventListener)
{
window.addEventListener("scroll",fn,false);
}
else
{
window.detachEvent("onscroll", fn);
}
};

/**
* window.onload绑定事件
* @param fn 需要绑定的function
*/
coos.window.onload = function(fn)
{
if (window.addEventListener)
{
window.addEventListener("load",fn,false);
}
else
{
window.attachEvent("onload", fn);
}
};

/**
* 让元素显示在屏幕中间,元素必须是绝对定位的
* @param obj 要显示的对象,改变top left 属性值
* @param event 触发的事件,在有滚动条的情况下必须传入事件以获取当时所在的滚动条高度
* @example
<style type="text/css">
html,body {margin: 0; padding: 0;height:100%;font-size: 14px;}
</style>
<script type="text/javascript">
function show(event)
{
var obj = document.getElementById("showDiv");
coos.window.center(obj,event);
//元素在屏幕中间距离顶部的高度
var top = coos.window.center.top(obj);
//固顶在屏幕上,不随滚动条变化
coos.window.fixed.set(obj,top);
coos.window.fixed();
}
</script>
<div id="showDiv" style="position:absolute;left:20px;top:5px;height:20px;400px;border:2px solid #ccc;text-align: center;clear: both;">
I'm a div,I can show and fixed in center!
</div>
<div style="clear: both;margin:80px;height:1000px;">
<br /><br />
<a href="javascript:void(0)" onclick="show(event)">show div center</a>
</div>
*/
coos.window.center = function(obj,event)
{
var e = event || window.event;
if(e)
{
obj.style.left = ((coos.window.width() - parseInt(obj.style.width,10))/2).toFixed() + "px";
var objh = (parseInt(obj.style.height,10)/2).toFixed();
var sh = parseInt(Math.max(document.body.scrollTop,document.documentElement.scrollTop),10);
var wh = parseInt((coos.window.height()/2).toFixed(),10);
var ch = sh + wh;
obj.style.top = (ch - objh) + "px";
}
else
{
obj.style.left = ((coos.window.width() - parseInt(obj.style.width,10))/2).toFixed() + "px";
obj.style.top = ((coos.window.height() - parseInt(obj.style.height,10))/2).toFixed() + "px";
}
};

/**
* 获取屏幕中间显示距离顶部的高度
*/
coos.window.center.top = function(obj)
{
return ((coos.window.height() - parseInt(obj.style.height,10))/2).toFixed();
};

/**
* 固顶元素在屏幕中显示,不随滚动条的变化而变化
*/
coos.window.fixed = function()
{
coos.window.onscroll.add(coos.window.fixed.bind);
};

/**
* 绑定需要固顶高度的元素window.onscroll事件
*/
coos.window.fixed.bind = function()
{
if(!coos.window.fixed.obj || !coos.window.fixed.top)
{
return;
}
var objs = coos.window.fixed.obj;
var tops = coos.window.fixed.top;
var len = objs.length;
//ie6.0以下不支持position:fixed;属性
if(coos.browser.msie && parseInt(coos.browser.version) <= 6)
{
for(var i = 0; i < len;i++)
{
var sh = parseInt(Math.max(document.body.scrollTop,document.documentElement.scrollTop),10);
objs[i].style.top = (sh + tops[i]) + "px";
}
}
else
{
for(var i = 0; i < len;i++)
{
objs[i].style.position = "fixed";
objs[i].style.top = tops[i] + "px";
}
//设置完position:fixed;属性和top属性后移除onscroll事件
coos.window.onscroll.remove(coos.window.fixed.bind);
}
};

/**
* 设置需要固定高度的元素
* @param obj 需要固定高度的元素对象
* @param top 需要固定高度的元素距离顶部的高度
*/
coos.window.fixed.set = function(obj,top)
{
if(!coos.window.fixed.obj)
{
coos.window.fixed.obj = new Array();
}
coos.window.fixed.obj.push(obj);

if(!coos.window.fixed.top)
{
coos.window.fixed.top = new Array();
}
top = parseInt(top,10);
coos.window.fixed.top.push(top);
};
原文地址:https://www.cnblogs.com/xxdotnet/p/2425435.html