本文实例讲述了JavaScript点击按钮后弹出透明浮动层的方法。分享给大家供大家参考。具体分析如下：
这里实现点击后页面变灰色，并用JS弹出一个居中的浮动层提示窗口，这个窗口是透明的，可以设置透明度，网上已经有很多类似的JavaScript代码，你可以借鉴一下。
<HTML>
<HEAD>
<TITLE>浮动层居中的对话框效果演示</TITLE>
<META http-equiv=Content-Type content="text/html; charset=utf-8">
<STYLE type=text/css>
HTML {
HEIGHT: 100%
}
BODY {
HEIGHT: 100%
}
BODY {
FONT-SIZE: 14px; FONT-FAMILY: Tahoma, Verdana, sans-serif
}
DIV.neat-dialog-cont {
Z-INDEX: 98; BACKGROUND: none transparent scroll repeat 0% 0%;
LEFT: 0px; WIDTH: 100%; POSITION: absolute; TOP: 0px; HEIGHT: 100%
}
DIV.neat-dialog-bg {
Z-INDEX: -1; FILTER: alpha(opacity=70); LEFT: 0px;
WIDTH: 100%; POSITION: absolute; TOP: 0px; HEIGHT: 100%;
BACKGROUND-COLOR: #eee; opacity: 0.7
}
DIV.neat-dialog {
BORDER-RIGHT: #555 1px solid; BORDER-TOP: #555 1px solid;
Z-INDEX: 99; MARGIN-LEFT: auto; BORDER-LEFT: #555 1px solid;
WIDTH: 30%; MARGIN-RIGHT: auto; BORDER-BOTTOM: #555 1px solid;
POSITION: relative; TOP: 25%; BACKGROUND-COLOR: #fff
}
DIV.neat-dialog-title {
PADDING-RIGHT: 0.3em; PADDING-LEFT: 0.3em; FONT-SIZE: 0.8em;
PADDING-BOTTOM: 0.1em; MARGIN: 0px; LINE-HEIGHT: 1.2em;
PADDING-TOP: 0.1em; BORDER-BOTTOM: #444 1px solid; POSITION: relative
}
IMG.nd-cancel {
RIGHT: 0.2em; POSITION: absolute; TOP: 0.2em
}
DIV.neat-dialog P {
PADDING-RIGHT: 0.2em; PADDING-LEFT: 0.2em;
PADDING-BOTTOM: 0.2em; PADDING-TOP: 0.2em; TEXT-ALIGN: center
}
</STYLE>
<SCRIPT type=text/javascript>
function NeatDialog(sHTML, sTitle, bCancel)
{
window.neatDialog = null;
this.elt = null;
if (document.createElement && document.getElementById)
{
var dg = document.createElement("div");
dg.className = "neat-dialog";
if (sTitle)
sHTML = '<div class="neat-dialog-title">'+sTitle+
((bCancel)?
'<img src="x.gif" alt="Cancel" class="nd-cancel" />':'')+
'</div>\n' + sHTML;
dg.innerHTML = sHTML;
var dbg = document.createElement("div");
dbg.id = "nd-bdg";
dbg.className = "neat-dialog-bg";
var dgc = document.createElement("div");
dgc.className = "neat-dialog-cont";
dgc.appendChild(dbg);
dgc.appendChild(dg);
if (document.body.offsetLeft > 0)
dgc.style.marginLeft = document.body.offsetLeft + "px";
document.body.appendChild(dgc);
if (bCancel) document.getElementById("nd-cancel").onclick = function()
{
window.neatDialog.close();
};
this.elt = dgc;
window.neatDialog = this;
}
}
NeatDialog.prototype.close = function()
{
if (this.elt)
{
this.elt.style.display = "none";
this.elt.parentNode.removeChild(this.elt);
}
window.neatDialog = null;
}
function openDialog()
{
var sHTML = '<p>你现在看到的是一个层窗口，是被JS控制弹出的</p>'+
'<p><button onclick="window.neatDialog.close()">关闭</button></p>';
new NeatDialog(sHTML, "你知道吗？", false);
}
</SCRIPT>
<BODY>
<H1>浮动层居中的效果</H1>
<BUTTON onclick=openDialog()>点此演示效果</BUTTON>
</BODY>
</HTML>
希望本文所述对大家的javascript程序设计有所帮助。
