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我正尝试创建一个基于前一个选择列表显示不同选择列表的表单。浏览器后退按钮否定了由javascript完成的CSS更改
HTML
<select name="college" id="college" onchange="show_majors()">
<!-- <option value="-">-</option> -->
<option value="COE">College of Engineering</option>
<option value="CBE">College of Business and Economics</option>
<option value="CS">College of Science</option>
<option value="CHSS">College of Humanities and Social Sciences</option>
<option value="CIT">College of Information Technology</option>
<option value="CEDU">College of Education</option>
<option value="CL">College of Law</option>
<option value="CFA">College of Food and Agriculture</option>
</select>
<div id="COE_MAJORS" class="majors">
<p><strong>Major:</strong></p>
<select name="COE_major" id="COE_major" onchange="show_clusters()">
<option value="OTHER">-</option>
</select>
</div>
<div id="CBE_MAJORS" class="majors">
<p><strong>Major:</strong></p>
<select name="CBE_major" id="CBE_major" onchange="show_clusters()">
<option value="OTHER">-</option>
</select>
</div>
.....
CSS
.majors {
height: 0px;
overflow: hidden;
}
的Javascript
<script type="text/javascript">
function show_majors() {
var college = document.getElementById("college");
college = college[college.selectedIndex].value;
var majors = document.getElementsByClassName("majors");
for(var i = 0; i < majors.length ; i++) {
majors[i].style.height = "0px";
}
if (college != "-") {
document.getElementById(college + "_MAJORS").style.height = "auto";
}
}
</script>
现在的问题是选择一所大学,然后一个重大按下提交按钮(这重定向到另一个页面后)。当我按下浏览器的后退按钮时,最后选择的大学仍然被选中,但专业DIV框被重置为0高度。如何在用户按下后退按钮时显示该相应大学的主要div框,以便它不会重置
您可以在状态存储在cookie或本地存储和基于它恢复它。 –