IE e.keyCode - 如何区分&符号和上箭头？ [英] IE e.keyCode - How can I differentiate between ampersand and up-arrow?

问题描述

我正在尝试修复jQuery UI小部件上的一个非常奇怪的javascript行为。
IE7（win XP），jQuery 1.2.6（是的，它是旧版本）。

I am fighting with a very strange javascript behavior on a jQuery UI widget I'm trying to fix. IE7 (win XP), jQuery 1.2.6 (yes, it's an old version).

小部件是一个组合框，可以捕获键盘事件并且箭头键有特殊行为。

The widget is a combo-box, which captures keyboard events and has special behaviors for the arrow keys.

当我尝试输入&时字符进入flexbox输入字段，我得到了奇怪的行为。

When I try to type the "&" character into the flexbox input field, I get strange behavior.

flexbox有一些代码如：

The flexbox has some code like:

//initialization
$myInputElement.keypress($.flexbox.process_key);
$.flexbox.process_key = function process_key(e) {
    $.flexbox.flexboxFromInput(this).processKey(e);
    return true;
};

//on the flexbox object's prototype:
...
    processKey: function processKey(e) {
        var mod = 0;
            if (typeof (e.ctrlKey) !== 'undefined') {
                if (e.ctrlKey) mod |= 1;
                if (e.shiftKey) mod |= 2;
            } else {
                if (e.modifiers & Event.CONTROL_MASK) mod |= 1;
                if (e.modifiers & Event.SHIFT_MASK) mod |= 2;
            }
            ...
            switch (e.keyCode) {
                   case 38: // up
                       this.prevResult();
                       break;
                   case 40: // down
                       if (this.getCtr().is(':visible')) this.nextResult();
                       else this.flexboxDelay(true);
                       break;
               ...etc.
           }
    }
...

当我介绍一个记录声明，我发现是按& （shift + 7）产生三个按键事件：

When I introduce a logging statement, what I find is that pressing "&" (shift+7) produces three keypress events:

INFO: Flexbox> processKey, keyCode=16, ctrl=false, shift=true
INFO: Flexbox> processKey, keyCode=55, ctrl=false, shift=true
INFO: Flexbox> processKey, keyCode=38, ctrl=false, shift=true

显然，keyCode 38都是up箭头键和&符号的ASCII代码??

Apparently, keyCode 38 is both the up arrow key and the ASCII code for ampersand??

当我写这篇文章时，我发现我可以将按键检测为shift + 7（keyCode 55） ）将它视为&符号键，然后设置某种标志以忽略下一个按键（即38）。这似乎是一个可怕的黑客。

As I was writing this, it occurred to me that I can detect the keypress as "shift+7" (keyCode 55) to treat it as the ampersand key, then set some kind of flag to ignore the next keypress (which is the 38). This seems like a horrible hack.

是否有人有更好的方法来区分特殊字符，如& IE中的箭头键？

Does anybody have a better way to differentiate between special characters such as "&" and the arrow keys in IE?

推荐答案

这就是我最终做的事情：

This is what I ended up doing:

    /*
     * Hack around a wierd behavior in IE where "&%'(" have the same keyCodes
     * as the arrow keys.
     */
        if (keyCodeIn(e.keyCode, 55, 53, 57) && (mod & 2) && !(mod & 1)) {
            this.ignoreNextArrowKey = true;
        }
        else if (222 === e.keyCode && !(mod & 2) && !(mod & 1)) {
            this.ignoreNextArrowKey = true;
        }
        else if (keyCodeIn(e.keyCode, 38, 37, 39, 40) && this.ignoreNextArrowKey) {
            this.ignoreNextArrowKey = false;
            return;
        }

        //...

        function keyCodeIn(keyCode) {
            for(var i = 1; i < arguments.length; i++) {
                if (arguments[i] === keyCode) {
                    return true;
                }
            }
            return false;
        }

希望这有助于某人。如果您正在重复使用此代码，则可能需要调整关键字this的使用情况，具体取决于它引用的对象（此处，它是与flexbox小部件关联的javascript对象）。

Hope this helps somebody. If you are reusing this code, you may have to adjust your usage of keyword 'this', depending on what object it refers to (here, it's a javascript object associated with the flexbox widget).

编辑：我更新了这段代码，并删除了之前存在的正则表达式测试，我发现它是错误的。

I updated this code, and removed the regular expression test that was previously there, which I discovered was buggy.

这篇关于IE e.keyCode - 如何区分&符号和上箭头？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！