一、disabled属性
在select上设置disabled="disabled",即可将下拉菜单变为只读状态,不可选择,点击也无效。
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<script src="jquery-3.4.1.js"></script>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>小白网页</title>
</head>
<body onLoad="HideWeekMonth()">
<div id="test">
<p class="invisible">评价小白:</p>
<select id="evaluate" name="evaluate" disabled="disabled"
data-options="height:24,width:80">
<option value="0">棒!</option>
<option value="1">很棒!</option>
<option value="2">非常棒!</option>
<option value="3">不许说不棒!</option>
<option value="5">棒棒棒棒棒…!</option>
</select>
</div>
</body>
</html>
注:这种方法会导致提交 form 表单时,select的值无法传递,提交前需移除disabled属性
$("#evaluate").removeAttr("disabled");
或
var evaluate=document.getElementById('evaluate');
evaluate.removeAttr("disabled");
添加disable属性可用:
$("#evaluate").attr("disabled","disabled");
二、设置选择无效
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<script src="jquery-3.4.1.js"></script>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>小白网页</title>
</head>
<body onLoad="HideWeekMonth()">
<div id="test">
<p class="invisible">评价小白:</p>
<select id="evaluate" name="evaluate" data-options="height:24,width:80"
οnfοcus="this.defaultIndex=this.selectedIndex;"
οnchange="this.selectedIndex=this.defaultIndex;">
<option value="0">棒!</option>
<option value="1">很棒!</option>
<option value="2">非常棒!</option>
<option value="3">不许说不棒!</option>
<option value="5">棒棒棒棒棒…!</option>
</select>
</div>
</body>
</html>
这种方法可以看到select选项,是通过配置 onfocus 和 onchange 让用户选择失效,只认默认值。