Javascript+css实现下拉菜单

<!--程序2-11-menu.html-->
<html>
<head>
    <title> 下拉菜单实例</title>
<script language = "javaScript">
//鼠标移动到菜单选项时显示对应的div
function show(menu)
{document.getElementById(menu).style.visibility = "visible";}
//当鼠标移出时隐藏所有div
function hide()
{document.getElementById("menu1").style.visibility = "hidden";
document.getElementById("menu2").style.visibility = "hidden";
document.getElementById("menu3").style.visibility = "hidden";
}
</script>
</head>
<body>
<table>
<tr bgcolor = "#9999FF" align = "center">
<td width = "120" onMouseMove = "show('menu1')" onMouseOut = "hide()">系列课程</td>
<td width = "120" onMouseMove = "show('menu2')" onMouseOut = "hide()">教学课件</td>
<td width = "120" onMouseMove = "show('menu3')" onMouseOut = "hide()">课程大纲</td>
</tr>
</table>
<div id = "menu1" onMouseMove = "show('menu1')" onMouseOut =  "hide()"
    style = "background:#9999ff;position:absolute;left:12;top=38;width=120;
    visibility : hidden">
    <span>c++</span><br>
    <span>java</span><br>
    <span>c#</span><br>
</div>
<div id = "menu2" onMouseMove = "show('menu2')" onMouseOut =  "hide()"
    style = "background:#9999ff;position:absolute;left:137;top=38;width=120;
    visibility : hidden">
    <span>c++课件</span><br>
    <span>java课件</span><br>
    <span>c#课件</span><br>
</div>
<div id = "menu3" onMouseMove = "show('menu3')" onMouseOut =  "hide()"
    style = "background:#9999ff;position:absolute;left:260;top=38;width=120;
    visibility : hidden">
    <span>c++大纲</span><br>
    <span>java大纲</span><br>
    <span>c#大纲</span><br>
</div>
</body>
</html>

 onMouseMove在鼠标移动时就会响应onMouseOver 在鼠标进入响应区域时响应

原文地址:https://www.cnblogs.com/gride-glory/p/7828068.html