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我正嘗試創建一個基於前一個選擇列表顯示不同選擇列表的表單。瀏覽器後退按鈕否定了由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>
現在的問題是選擇一所大學,然後一個重大按下提交按鈕(這重定向到另一個頁面後)。當我按下瀏覽器的後退按鈕時,最後選擇的大學仍然被選中,但專業DIV框被重置爲0高度。如何在用戶按下後退按鈕時顯示該相應大學的主要div框,以便它不會重置
您可以在狀態存儲在cookie或本地存儲和基於它恢復它。 –