<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<p>copy the code</p>
<p id="result"></p>
</body>
<script>
document.addEventListener('copy', function (event) {
// clipboardData 对象是为通过编辑菜单、快捷菜单和快捷键执行的编辑操作所保留的，也就是你复制或者剪切内容
let clipboardData = event.clipboardData || window.clipboardData;
if (!clipboardData) { return; }
let text = window.getSelection().toString();
let join = "\n\n******** 内容拼接 ********";
if (text) {
// 如果文本存在，首先取消文本的默认事件
event.preventDefault();
clipboardData.setData('text/plain', text + join);
document.querySelector('#result').innerText = text + join;
}
});
</script>
</html>