防止默认事件操作不起作用...？

I'm trying to add keyboard shortcuts on my website to make fast navigation possible using the keyboard. I'm running into a slight problem, however, with my attempted Alt+X shortcut. The event runs just fine and returns false as it should, but the browser's File menu comes up regardless. I've also tried the preventDefault method, but no change.

该脚本的精简版本是：

document.documentElement.onkeydown = function(e) {
    e = e || window.event;
    switch( e.keyCode || e.which) {
        // some cases here - most notably:
        case 116: // F5 key
            if( activeFrame) {
                activeFrame.contentWindow.location.reload();
                // reloads an iframe if one is active
                return false;
            }
            break;
        // more cases...
        case 88: // X key
            if( e.altKey) {
                // do something
                return false;
            }
    }
}

As noted above, overriding the default action of the F5 key works just fine - the browser reloads the page only if no iframe is active. I don't quite see how to prevent the menu from appearing when Alt+X is pressed.

use stopPropagation(e);代替preventDefault method

function stopPropagation(e)
{
    e = e || event;/* get IE event ( not passed ) */
    e.stopPropagation? e.stopPropagation() : e.cancelBubble = true;
}

参考链接 http://www.webmasterworld.com/forum91/4610.htm

另一个SO问题提到了这一点防止默认 https://stackoverflow.com/questions/1000597/event-preventdefault-function-not-working-in-ie-any-helpIE 中有问题。

UPDATE

尝试使用下面的代码MSDN 参考 http://msdn.microsoft.com/en-us/library/ms536938%28v=vs.85%29.aspx

event.returnValue=false;

还有一些点来自检测击键 http://www.quirksmode.org/js/keys.html

一些一般注意事项：

• 一般来说，Mac 的可靠性不如 Windows，并且某些按键无法检测到。
• 资源管理器不会触发删除、结束、输入、转义、功能键、主页、插入、向上/向下翻页和选项卡的按键事件。
• Onkeypress，Safari 为删除、结束、功能键、home 和 pageUp.Down 提供了 63200 范围内的奇怪 keyCode 值。 onkeydown 和 -up 值正常。
• 除 Opera 外，Mac 上无法检测到 Alt、Cmd、Ctrl 和 Shift。但是，您始终可以使用 altKey、ctrlKey 和 shiftKey 属性。