代码示例:(标识:eg_js_events_keycode)
<!DOCTYPE html>
<html>
<head>
<script>
function whichButton(event) {
  document.getElementById("demo").innerHTML = event.keyCode;
}
</script>
</head>

<body onkeyup="whichButton(event)">

<p><b>注释:</b>尝试此示例时,请确保右框架具有焦点!</p>

<p>单击此页面,然后按键盘上的键。</p>

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

</body>
</html>
运行结果: