Capturing onkeydown in Javascript

后端未结

关注

 2  1889

I have a web front-end to an AS/400 CGI application which allows the use of some of the F1-F24 keys (depending on the page) as well as page-up, page-do

相关标签:

2条回答

执笔经年

2021-01-07 06:47

UPDATED

I've sorted this out now. Sorry for removing the context for the comments below, but hey, the previous versions are still there.

It turns out that there are two problems to be fixed in IE: first is that contrary to what I said before, putting an onkeydown attribute in the <body> doesn't work. You need to attach it to the document instead. The second issue is that IE won't let you suppress magic behaviour such as the search dialog triggered by the F3 key unless you do an evil hack involving changing the keydown event's keyCode property, which is clearly a Very Wrong Thing Indeed. Be that as it may, remove the onkeydown attribute in the <body> and the following should do the job (now amended to work in Opera also):

var keyCodeMap = {
    "1013": "EN",
    "1033": "UP",
    "1034": "DN",
    "1112": "01",
    "1113": "02",
    "1114": "03"
    // ...(F4 thru F24 here)...
};

var suppressKeypress = false;

function setCmdKey(e) {
    e = e || window.event;
    var wrkkeyCode = e.keyCode;
    if (wrkkeyCode != 13 &&
        wrkkeyCode != 33 &&
        wrkkeyCode != 34 &&
        wrkkeyCode != 27 &&
        wrkkeyCode < 112) return;

    wrkkeyCode += 1000;

    if (e.shiftKey) wrkkeyCode += 1000;
    var cmdkeycode = keyCodeMap[wrkkeyCode];
    if (!cmdkeycode) return; /* Anything else should be ignored */

    var input = document.forms[0].elements["CmdKey"];
    input.value = "F" + cmdkeycode;
    input.name = "_K" + cmdkeycode;

    try {
        // Prevent default action in IE by bad hacky means
        e.keyCode = 0;
    } catch (ex) {
        // Other browsers do not allow setting the keyCode
    }
    suppressKeypress = true;

    if (ONSUBMITFUN()) document.forms[0].submit();
    return false;
}

document.onkeydown = setCmdKey;
document.onkeypress = function() {
    if (suppressKeypress) {
        return false;
    }
};

0 讨论(0)

礼貌的吻别

2021-01-07 07:00

You should always return false from event handlers even if you have prevented default by modifying the event, see Quirks mode for more information.

0 讨论(0)
发布评论:

提交评论
- 加载中...