javascript - 如何检测文本区域上箭头键的按下事件？

Question

创建以下 html 页面:

<textarea id="code" rows="10"></textarea>
<script>
  document.onkeydown = function(event) {
    alert(event.keyCode);
  }
</script>

在 Mobile Safari(在模拟器或带键盘的设备上)上打开它，点击文本区域开始编辑。现在按任意箭头键 - 事件不会触发。

如何检测方向键的向下键？

附言Apple Bug Report 系统的相关问题:13243285

Answer 1

苹果官方回答:

Thank you for contacting Apple Developer Technical Support (DTS). Our engineers have reviewed your request and have concluded that there is no supported way to achieve the desired functionality given the currently shipping system configurations.