[读码时间] 按下键盘显示keyCode

说明：代码取自网络
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title>按下键盘显示keyCode</title>
    <style>
        body{
            text-align:center;
            font:30px/1.5 5fae8f6f96c59ed1,arial;
        }
        pre{
            color:green;
            padding:10px 15px;
            background:#f0f0f0;
            border:1px dotted #333;
            font:12px/1.5 Courier New;
            text-align:left;
        }
        span{
            color:#999;
        }
    </style>
    <script>
        window.onload = function () {
            var oP = document.getElementsByTagName("p")[0];
            document.onkeydown = function (event) {
                var event = event || window.event;
                oP.innerHTML = event.keyCode;
                return false;
            }
        }
    </script>
</head>
<body>
    <pre>
        &lt;script type="text/javascript"&gt;
window.onload = function ()
{
    var oP = document.getElementsByTagName("p")[0];    
    document.onkeydown = function (event)
    {
        var event = event || window.event;
        oP.innerHTML = event.keyCode;
        return false
    }
}
&lt;/script&gt;</pre>
    <p>这里将显示您按下键的 keyCode</p>
</body>
</html>