键盘事件：altKey 属性

KeyboardEvent.altKey 只读属性是一个布尔值，指示当事件发生时 alt 键（在 macOS 上为 Option 或 ⌥）是否被按下 (true) 或未被按下 (false)。

值

一个布尔值。

示例

html

<!doctype html>
<html lang="en-US">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width" />
    <title>altKey example</title>

    <script>
      function showChar(e) {
        alert(
          "Key KeyDown: " +
            String.fromCharCode(e.charCode) +
            "\n" +
            "charCode: " +
            e.charCode +
            "\n" +
            "ALT key KeyDown: " +
            e.altKey +
            "\n",
        );
      }
    </script>
  </head>

  <body onkeydown="showChar(event);">
    <p>
      Press any character key, with or without holding down the ALT key.<br />
      You can also use the SHIFT key together with the ALT key.
    </p>
  </body>
</html>

规范

规范
UI 事件 # dom-keyboardevent-altkey

浏览器兼容性

BCD 表格仅在启用 JavaScript 的浏览器中加载。

另请参阅

KeyboardEvent