用JavaScript实现仿Windows关机效果_javascript技巧

元素。
selects = document.getElementsByTagName('select');
for(i = 0; i < selects.length; i++) {
selects[i].style.visibility = visibility;
}



代码实现


客户端代码
客户端的页面上有两个链接，用户单击链接后，向服务器端发送请求，并将返回信息显示到高亮层上。客户端的网页文件代码如下所示：

• One
  


• Two
  

另外，还需要设置该页面所使用CSS样式。lightbox.css样式表文件代码如下所示：
#lightbox {
BORDER-RIGHT: #fff 1px solid;
BORDER-TOP: #fff 1px solid;
DISPLAY: none;
Z-INDEX: 9999;
BACKGROUND: #fdfce9;
LEFT: 50%;
MARGIN: -220px 0px 0px -250px;
BORDER-LEFT: #fff 1px solid;
WIDTH: 500px;
BORDER-BOTTOM: #fff 1px solid;
POSITION: absolute;
TOP: 50%;
HEIGHT: 400px;
TEXT-ALIGN: left
}
UNKNOWN {
POSITION: fixed
}
#overlay {
DISPLAY: none;
Z-INDEX: 5000; FILTER: alpha(opacity=80);
LEFT: 0px;
WIDTH: 100%;
POSITION: absolute;
TOP: 0px;
HEIGHT: 100%;
BACKGROUND-COLOR: #000; moz-opacity: 0.8; opacity: .80
}
UNKNOWN {
POSITION: fixed
}
.done#lightbox #lbLoadMessage {
DISPLAY: none
}
.done#lightbox #lbContent {
DISPLAY: block
}
.loading#lightbox #lbContent {
DISPLAY: none
}
.loading#lightbox #lbLoadMessage {
DISPLAY: block
}
.done#lightbox IMG {
WIDTH: 100%; HEIGHT: 100%
}
客户端脚本
由于浏览器对图层的支持不同，所以首先要确定客户端浏览器的类型。以下代码可用于判断客户端的浏览器和操作系统。
var detect = navigator.userAgent.toLowerCase();
var OS,browser,version,total,thestring;

function getBrowserInfo() {
if (checkIt('konqueror')) {
browser = "Konqueror";
OS = "Linux";
}
else if (checkIt('safari')) browser = "Safari"
else if (checkIt('omniWeb')) browser = "OmniWeb"
else if (checkIt('opera')) browser = "Opera"
else if (checkIt('Webtv')) browser = "WebTV";
else if (checkIt('icab')) browser = "iCab"
else if (checkIt('msie')) browser = "Internet Explorer"
else if (!checkIt('compatible')) {
browser = "Netscape Navigator"
version = detect.charAt(8);
}
else browser = "An unknown browser";

if (!version) version = detect.charAt(place + thestring.length);

if(!OS) {
if (checkIt('linux')) OS = "Linux";
else if (checkIt('x11')) OS = "Unix";
else if (checkIt('mac')) OS = "Mac"
else if (checkIt('win')) OS = "Windows"
else OS = "an unknown operating system";
}
}

function checkIt(string) {
place = detect.indexOf(string) + 1;
thestring = string;
return place;
}
下面看一下网页加载时需要添加的方法。有关网页加载和初始化方法代码如下：
//网页加载调用initialize和getBrowserInfo方法
Event.observe(window, 'load', initialize, false);
Event.observe(window, 'load', getBrowserInfo, false);
//未加载时清空缓存
Event.observe(window, 'unload', Event.unloadCache, false);
//初始化方法
function initialize(){
//调用该方法为该页添加覆盖层和高亮显示层
addLightboxMarkup();
//为每个可高亮显示的元素创建lightbox对象
lbox = document.getElementsByClassName('lbOn');
for(i = 0; i < lbox.length; i++) {
valid = new lightbox(lbox[i]);
}
}

// 使用Dom方法创建覆盖层和高亮层
function addLightboxMarkup() {
bod = document.getElementsByTagName('body')[0];
overlay = document.createElement('div');
overlay.id = 'overlay';
lb = document.createElement('div');
lb.id = 'lightbox';
lb.className = 'loading';
lb.innerHTML = '

' +
'

Loading

' +
'

';
bod.appendChild(overlay);
bod.appendChild(lb);
}
封装lightbox类
初始化数据时，为每个可高亮显示的链接创建了lightbox对象。该类的代码具体实现如下：
var lightbox = Class.create();

lightbox.prototype = {
yPos : 0,
xPos : 0,
//构造方法,ctrl为创建该对象的元素
initialize: function(ctrl) {
//将该元素的链接赋值给this.content
this.content = ctrl.href;
//为该元素添加onclick事件activate方法
Event.observe(ctrl, 'click', this.activate.bindAsEventListener(this), false);
ctrl.onclick = function(){return false;};
},

//当单击链接时
activate: function(){
if (browser == 'Internet Explorer'){//判断为IE浏览器
this.getScroll();
this.prepareIE('100%', 'hidden');
this.setScroll(0,0);
this.hideSelects('hidden');//隐藏所有的

Porsche Carrera GT

The Carrera GT has a 5.7 litre V10 internal combustion engine that produces
605 SAE horsepower (451 kW). Porsche claims it will accelerate from 0 to 100
km/h (62 mph) in 3.9 seconds and has a maximum speed of 330 km/h (204 mph).
With 605 hp, the car weighs 1,380 kg (3,042 lb). The Carrera GT is only
offered with a six-speed manual transmission, in contrast to its rival the
Ferrari Enzo that is only offered with sequential manual transmission. Also
the Carrera GT is significantly less expensive than the Ferrari Enzo. The
Ferrari Enzo is priced around $660,000 to the Carrera GT's $440,000. The
Carrera GT is known for its high quality and reliability which makes it one of
the best supercars ever.
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Ferrari Testarossa

The Ferrari Testarossa is an V12 mid-engined sports car made by Ferrari.
The name, which means "red head", comes from the red painted cylinder heads on
the flat-12 engine. The engine was technically a 180?V engine since it shared
flat-plane crankshaft pins with opposing cylinders. Output was 390 hp (291
kW), and the car won many comparison tests and admirers - it was featured on
the cover of Road & Track magazine nine times in just five years. Almost
10,000 Testarossas, 512TRs, and 512Ms were produced, making this one of the
most common Ferrari models despite its high price and exotic design.
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