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>'+sTitle+ ((bCancel)? '<img src="x.gif" alt="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>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。