Detecting Arrow key press in IE via javascript/jQu

2019-01-24 02:52发布

站内问答 / JavaScript
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I'm trying to set up a menu that can be navigated via the arrow keys. I have this working fin in Firefox.

Trying to get it to work in IE8 and after a bit of struggle, found that it was because IE8 wouldn't register a keypress on the arrows. To test:

$(document).keypress(function (eh){ 
    alert(eh.keyCode);
};

In Firefox, pressing any of the arrow keys would trigger an alert of 37, 38, 39 or 40.

In IE8, nothing. Any other key on the standard QWERTY keyboard would register, but not the arrow keys.

Is this an issue with my Javascript? A browser setting? A Windows setting?

4条回答
兄弟一词,经得起流年.
2楼-- · 2019-01-24 03:18

From the jQuery keypress documentation (the last paragraph of the introductory text):

Note that keydown and keyup provide a code indicating which key is pressed, while keypress indicates which character was entered. For example, a lowercase "a" will be reported as 65 by keydown and keyup, but as 97 by keypress. An uppercase "A" is reported as 97 by all events. Because of this distinction, when catching special keystrokes such as arrow keys, .keydown() or .keyup() is a better choice.

It even literally mentions about the arrow keys ;) Thus, you really need to hook on either the keydown or keyup events. Here's an SSCCE with keydown, just copy'n'paste'n'run it. No, you don't need to do a browser-compatible check on the event, this works in all browsers from IE6 up to with Firefox.

<!doctype html>
<html lang="en">
    <head>
        <title>SO question 2217553</title>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
        <script>
            $(document).keydown(function(event) {
                switch (event.keyCode) {
                    case 37: alert('left'); break;
                    case 38: alert('up'); break;
                    case 39: alert('right'); break;
                    case 40: alert('down'); break;
                }
            });
        </script>
    </head>
    <body>
       <p>Press one of the arrow keys.</p> 
    </body>
</html>
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Luminary・发光体
3楼-- · 2019-01-24 03:25

Try this:

$(document).keydown(function (e) {
    if(!e) {
        e = window.event;
    }
    switch(e.keyCode) {
    case 37:
        goLeft();
        break;
    case 39:
        goRight();
        break;
    }
});
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小情绪 Triste *
4楼-- · 2019-01-24 03:30

Because I sometimes do not want events to bubble for some keys, I use something like: Customize the codes/keys as you see fit.

/* handle special key press */
function checkCptKey(e)
{
    var shouldBubble = true;
    switch (e.keyCode)
    {
        // user pressed the Tab                                                                                                                                        
        case 9:
            {
                $(".someSelect").toggleClass("classSelectVisible");
                shouldBubble = false;
                break;
            };
            // user pressed the Enter    
        case 13:
            {
                $(".someSelect").toggleClass("classSelectVisible");
                break;
            };
            // user pressed the ESC
        case 27:
            {
                $(".someSelect").toggleClass("classSelectVisible");
                break;
            };
    };
    /* this propogates the jQuery event if true */
    return shouldBubble;
};

/* user pressed special keys while in Selector */
$(".mySelect").keydown(function(e)
{
    return checkCptKey(e);
});
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Deceive 欺骗
5楼-- · 2019-01-24 03:39

Use the 'keydown' event

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