代码示例:(标识:event_oncopy)
<!DOCTYPE html>
<html>
<body>

<input type="text" oncopy="myFunction()" value="尝试复制此文本">

<p id="demo"></p>

<script>
function myFunction() {
  document.getElementById("demo").innerHTML = "你复制了文本!"
}
</script>

</body>
</html>
运行结果: