解决方法
以下是一个简单的JavaScript示例：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Basic modal demo</title>
<style type="text/css">
body { margin: 0; }
#shade,#modal { display: none; }
#shade { position: fixed; z-index: 100; top: 0; left: 0; width: 100%; height: 100%; }
#modal { position: fixed; z-index: 101; top: 33%; left: 25%; width: 50%; }
#shade { background: silver; opacity: 0.5; filter: alpha(opacity=50); }
</style>
</head>
<body>
<div id="shade"></div>
<div id="modal">
<textarea rows="5" cols="25"></textarea>
<button id="close">Close</button>
</div>
<p>
<button id="start">Start</button>
</p>
<script type="text/javascript">
var modal= document.getElementById('modal');
var shade= document.getElementById('shade');
document.getElementById('start').onclick= function() {
modal.style.display=shade.style.display= 'block';
};
document.getElementById('close').onclick= function() {
modal.style.display=shade.style.display= 'none';
};
// This code is a workaround for IE6's lack of support for the
// position: fixed style.
//
if (!('maxHeight' in document.body.style)) {
function modalsize() {
var top= document.documentElement.scrollTop;
var winsize= document.documentElement.offsetHeight;
var docsize= document.documentElement.scrollHeight;
shade.style.height= Math.max(winsize,docsize)+'px';
modal.style.top= top+Math.floor(winsize/3)+'px';
};
modal.style.position=shade.style.position= 'absolute';
window.onscroll=window.onresize= modalsize;
modalsize();
}
</script>
</body>
</html>
您可以从中进行各种改进,例如iframe可以修复IE z-indexing,或将其封装在可重用的对象中,但这是完成的基本方法.
