获取Javascript中所有当前按下的键的列表 [英] Get a list of all currently pressed keys in Javascript

问题描述

在Javascript中，我想编写一个函数，返回当前按下的所有键的列表（这样我就可以允许用户创建自定义键盘快捷键。）有没有办法获取当前所有按键的列表Javascript中的键？

In Javascript, I want to write a function that returns a list of all keys that are currently pressed (so that I can allow the user to create custom keyboard shortcuts.) Is there any way to obtain a list of all currently pressed keys in Javascript?

推荐答案

• 每按一次键 keydown 将发送活动


• 每当发布密钥时， keyup 活动将被触发


• whenever a key is pressed a keydown event will be sent
• whenever a key is released a keyup event will be triggered

因此，您只需将密钥保存在一个数组中，然后检查您的组合是否为真。

So you just need to save the keys in an array and check whether your combination is true.

var keys = [];
window.addEventListener("keydown",
    function(e){
        keys[e.keyCode] = true;
        checkCombinations(e);
    },
false);

window.addEventListener('keyup',
    function(e){
        keys[e.keyCode] = false;
    },
false);

function checkCombinations(e){
    if(keys["a".charCodeAt(0)] && e.ctrlKey){
        alert("You're not allowed to mark all content!");
        e.preventDefault();
    }
}

请注意，您应该使用 e.key 而不是 e.keyCode 尽可能（在这种情况下 var key = {} ，因为 e.key 是一个字符串）。

Note that you should use e.key instead of e.keyCode whenever possible (in this case var key = {}, since e.key is a string).

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