下拉菜单--二级联动菜单练习

系统管理员 2022-05-14 13:42 299阅读 0赞

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
    <title>无标题文档</title>
    
    <style type="text/css">
    
    select{
    	width:100px;
    	}
    	
    </style>
    
    <script type="text/javascript">
    function selcity()
    {
    	var arr = [[],['海淀区', '朝阳区', '东城区', '西城区']
    	,['沈阳', '大连', '鞍山', '抚顺']
    	,['济南', '青岛', '烟台', '威海']
    	,['石家庄', '廊坊', '唐山', '秦皇岛']];
    	
    	//获取选择的省的角标
    	var selNode = document.getElementById("selid");
    	var index = selNode.selectedIndex;
    	var cities = arr[index];
    	
    	var subSelNode = document.getElementById("subselid");
    	
    	//有更简单的清除方式，只要改变下拉菜单的长度即可
    	subSelNode.options.length = 0;
    	
    	/*
    	//清除上一次选择的子菜单的内容
    	for(var x = 1; x < subSelNode.options.length;)
    	{
    		subSelNode.removeChild(subSelNode.options[x]);
    	}
    	*/
    	
    	for(var x = 0; x < cities.length; x++)
    	{
    		var optNode = document.createElement("option");
    		optNode.innerHTML = cities[x];
    		subSelNode.appendChild(optNode);
    	}
    }
    </script>
    
    </head>
    
    <body>
    
    <select id="selid" οnchange="selcity()">
    	<option>--选择省市--</option>
    	<option>北京市</option>
    	<option>辽宁省</option>
    	<option>山东省</option>
    	<option>河北省</option>
    </select>
    <select id="subselid">
    	<option>--选择城市--</option>
    </select>
    </body>
    </html>

运行结果：

![1354543602_6279.jpg][]

[1354543602_6279.jpg]: https://img-my.csdn.net/uploads/201212/03/1354543602_6279.jpg