模拟按住Ctrl键 [英] Simulate Holding Ctrl Key

问题描述

我正在尝试更改多重选择元素的默认行为，以便用户可以选择并取消选择多个值，而无需一直按下 Ctrl 键。

我发现一个简单的解决方案这里，但是这在ie8中不起作用（因为在ie中， onmousedown 不适用于选项元素）。

但是我想，只要鼠标悬停在多重选择上，可以模拟一个按下的控制键：

  $（document）.ready（function（）{
 $（'select'）。hover（function（e）{
 var kde = jQuery.Event （keydown）; 
 kde.ctrlKey = true; //这样的东西
 kde.keyCode = 17; //或者 - 我不知道
 $（e.target ）.trigger（kde）; 
}）; 
}）; 
  

为什么这不起作用？

• 是否直接再次发布 Ctrl 键？


• 代码有问题吗？

<我完全没有其他的东西吗？

解决方案

以编程方式推动键盘按钮，就像用户在键盘上推送一个键时，通过模拟 shift 键不能产生大写A。此外，即使它将将工作不起作用：在Mac上，您按 cmd 而不是 ctrl 选择多个元素。 p>

所以不幸的是，你必须删除这种方法，并寻找其他选项。

I'm currently trying to change the default behaviour of a multiselect element, so that a user can select and deselect multiple values, without having to press the Ctrl key all the while.

I found a simple solution here, but this does not work in ie8 (because in ie, the onmousedown does not apply to option elements).

But I figured, that one could just simulate a pressed control key, whenever the mouse hovers over a multiselect:

$(document).ready(function() {
    $('select').hover(function(e) {
        var kde = jQuery.Event("keydown");
        kde.ctrlKey = true;  //something like this
        kde.keyCode = 17;    //or this - i don't know
        $(e.target).trigger(kde);        
    });
});

Why does this not work?

• Is the Ctrl key directly being released again?
• Is something wrong with the code?
• Am I missing something else entirely?

解决方案

You can't simulate such events by programmatically pushing keyboard buttons, just like you can't produce a capital A by simulating the shift key while the user pushes the a key on their keyboard. Besides, even if it would work it wouldn't work: on Macs you press cmd, not ctrl, to select multiple elements.

So unfortunately you'll have to drop this approach and look for other options.

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