刚开始接触menu控件，感觉怎么这么别扭啊。

首先说数据访问部分，为了所谓的provider pattern，一层一层的包装，而且都是些黑盒子，虽然概念是挺先进，结构好象也很清楚，但还是让我觉的迷迷糊糊，至于嘛，只是想做几个数据驱动的menu而已。还有那个前台的menu类，那么多的Properties，尤其想到menu类也是个黑盒子，一点都不知道，它生成的xhtml会是什么样的，而我只有一点点css知识而已，想到这里连尝试的欲望都没了。还不如自己动手亲自写一个menu呢，网上好象有好多现成的javascript类，比如这个：

Div_css 结构的，虽然没有asp.net 控件那么漂亮，可也很是实用，至少都是透明的。不过后台有点麻烦，当时的想法是：

1 设计一个类sitemap，从数据库里读导航信息，然后存到一个dataset中，

2 在application_start 事件处理函数中 实例化一个sitemap 和一个sqlCachedependency ，插入到cache中。

3 一个dependency的回调函数,以更新cache中的数据

4 从cache中提取数据生成menu。

这样一来可以想象default.master的代码的代码会乱七八糟。非但不太容易写，写好的代码也不太容易复用。而且还有关于cache的很多问题。

肯定有其他办法，asp.net好多东西我都没有接触过。不过现在想想 provider pattern还是不错，一层api连接表示层，一层api连接数据访问层。

被迫学习menu类，希望它不要太让人意外。终于明白为什么开源让那么多人激动，开放透明啊！

/**//*****************************************************
* ypSlideOutMenu
* 3/04/2001
*
* a nice little script to create exclusive, slide-out
* menus for ns4, ns6, mozilla, opera, ie4, ie5 on
* mac and win32. I've got no linux or unix to test on but
* it should(?) work...
*
* Revised:
* - 08/29/2002 : added .hideAll()
* - 04/15/2004 : added .writeCSS() to support more
*
    
        
            
                than 30 menus.
*
* --youngpup--
*****************************************************/
ypSlideOutMenu.Registry = []
ypSlideOutMenu.aniLen = 250
ypSlideOutMenu.hideDelay = 1000
ypSlideOutMenu.minCPUResolution = 10
// constructor
function ypSlideOutMenu(id, dir, left, top, width, height)
...{
this.ie = document.all ? 1 : 0
this.ns4 = document.layers ? 1 : 0
this.dom = document.getElementById ? 1 : 0
if (this.ie || this.ns4 || this.dom) ...{
this.id = id
this.dir = dir
this.orientation = dir == "left" || dir == "right" ? "h" : "v"
this.dirType = dir == "right" || dir == "down" ? "-" : " "
this.dim = this.orientation == "h" ? width : height
this.hideTimer = false
this.aniTimer = false
this.open = false
this.over = false
this.startTime = 0
this.gRef = "ypSlideOutMenu_" id
eval(this.gRef "=this")
ypSlideOutMenu.Registry[id] = this
var d = document
var strCSS = "";
strCSS  = '#'   this.id   'Container { visibility:hidden; '
strCSS  = 'left:'   left   'px; '
strCSS  = 'top:'   top   'px; '
strCSS  = 'overflow:hidden; z-index:10000; }'
strCSS  = '#'   this.id   'Container, #'   this.id   'Content { position:absolute; '
strCSS  = 'width:'   width   'px; '
strCSS  = 'height:'   height   'px; '
strCSS  = 'clip:rect(0 '   width   ' '   height   ' 0); '
strCSS  = '}'
this.css = strCSS;
this.load()
}
}
ypSlideOutMenu.writeCSS = function() ...{
document.writeln('<style type="text/css">');
for (var id in ypSlideOutMenu.Registry) ...{
document.writeln(ypSlideOutMenu.Registry[id].css);
}
document.writeln('</style>');
}
ypSlideOutMenu.prototype.load = function() ...{
var d = document
var lyrId1 = this.id   "Container"
var lyrId2 = this.id   "Content"
var obj1 = this.dom ? d.getElementById(lyrId1) : this.ie ? d.all[lyrId1] : d.layers[lyrId1]
if (obj1) var obj2 = this.ns4 ? obj1.layers[lyrId2] : this.ie ? d.all[lyrId2] : d.getElementById(lyrId2)
var temp
if (!obj1 || !obj2) window.setTimeout(this.gRef   ".load()", 100)
else ...{
this.container = obj1
this.menu = obj2
this.style = this.ns4 ? this.menu : this.menu.style
this.homePos = eval("0"   this.dirType   this.dim)
this.outPos = 0
this.accelConst = (this.outPos - this.homePos) / ypSlideOutMenu.aniLen / ypSlideOutMenu.aniLen
// set event handlers.
if (this.ns4) this.menu.captureEvents(Event.MOUSEOVER | Event.MOUSEOUT);
this.menu.onmouseover = new Function("ypSlideOutMenu.showMenu('"   this.id   "')")
this.menu.onmouseout = new Function("ypSlideOutMenu.hideMenu('"   this.id   "')")
//set initial state
this.endSlide()
}
}
ypSlideOutMenu.showMenu = function(id)
...{
var reg = ypSlideOutMenu.Registry
var obj = ypSlideOutMenu.Registry[id]
if (obj.container) ...{
obj.over = true
for (menu in reg) if (id != menu) ypSlideOutMenu.hide(menu)
if (obj.hideTimer) ...{ reg[id].hideTimer = window.clearTimeout(reg[id].hideTimer) }
if (!obj.open && !obj.aniTimer) reg[id].startSlide(true)
}
}
ypSlideOutMenu.hideMenu = function(id)
...{
var obj = ypSlideOutMenu.Registry[id]
if (obj.container) ...{
if (obj.hideTimer) window.clearTimeout(obj.hideTimer)
obj.hideTimer = window.setTimeout("ypSlideOutMenu.hide('"   id   "')", ypSlideOutMenu.hideDelay);
}
}
ypSlideOutMenu.hideAll = function()
...{
var reg = ypSlideOutMenu.Registry
for (menu in reg) ...{
ypSlideOutMenu.hide(menu);
if (menu.hideTimer) window.clearTimeout(menu.hideTimer);
}
}
ypSlideOutMenu.hide = function(id)
...{
var obj = ypSlideOutMenu.Registry[id]
obj.over = false
if (obj.hideTimer) window.clearTimeout(obj.hideTimer)
obj.hideTimer = 0
if (obj.open && !obj.aniTimer) obj.startSlide(false)
}
ypSlideOutMenu.prototype.startSlide = function(open) ...{
this[open ? "onactivate" : "ondeactivate"]()
this.open = open
if (open) this.setVisibility(true)
this.startTime = (new Date()).getTime()
this.aniTimer = window.setInterval(this.gRef   ".slide()", ypSlideOutMenu.minCPUResolution)
}
ypSlideOutMenu.prototype.slide = function() ...{
var elapsed = (new Date()).getTime() - this.startTime
if (elapsed > ypSlideOutMenu.aniLen) this.endSlide()
else ...{
var d = Math.round(Math.pow(ypSlideOutMenu.aniLen-elapsed, 2) * this.accelConst)
if (this.open && this.dirType == "-") d = -d
else if (this.open && this.dirType == " ") d = -d
else if (!this.open && this.dirType == "-") d = -this.dim   d
else d = this.dim   d
this.moveTo(d)
}
}
ypSlideOutMenu.prototype.endSlide = function() ...{
this.aniTimer = window.clearTimeout(this.aniTimer)
this.moveTo(this.open ? this.outPos : this.homePos)
if (!this.open) this.setVisibility(false)
if ((this.open && !this.over) || (!this.open && this.over)) ...{
this.startSlide(this.over)
}
}
ypSlideOutMenu.prototype.setVisibility = function(bShow) ...{
var s = this.ns4 ? this.container : this.container.style
s.visibility = bShow ? "visible" : "hidden"
}
ypSlideOutMenu.prototype.moveTo = function(p) ...{
this.style[this.orientation == "h" ? "left" : "top"] = this.ns4 ? p : p   "px"
}
ypSlideOutMenu.prototype.getPos = function(c) ...{
return parseInt(this.style[c])
}
ypSlideOutMenu.prototype.onactivate = function() ...{ }
ypSlideOutMenu.prototype.ondeactivate = function() ...{ }