如何在iframe中禁用右键单击

Question

嗨，我正在尝试禁用Ifram区域，但无法正常工作，我正在使用此代码。请帮我解决这个问题

<iframe id="fid" src="https://data.testprepkart.com/IB/IB%20Online%20Preparation/1_Extended%20Essay/1_The%20Basics.pdf?page=hsn#toolbar=0" width="800px" height="600px"></iframe>


<script src="https://ajax.aspnetcdn.com/ajax/jQuery/jquery-3.3.1.min.js"></script>
<script type="text/javascript">$(document).ready(function() {
$("iframe").on("contextmenu",function(){
   return false;
}); }); </script>