确定JavaScript e.keyCode是否是可打印（非控制）字符 [英] Determine if JavaScript e.keyCode is a printable (non-control) character

问题描述

我只想知道与可输入字符对应的JavaScript keyCode 的范围;或者，不可输入（控制）字符的范围，如退格，转义，命令，移位等，所以我可以忽略它们。

I'd just like to know the range(s) of JavaScript keyCodes that correspond to typeable characters; or alternatively, the range of non-typeable (control) characters like backspace, escape, command, shift, etc. so I can ignore them.

我问的原因是调用 String.fromCharCode（）会导致控制键出现奇数字符。例如，左侧命令为[，左箭头为％。很奇怪。

The reason I ask is calling String.fromCharCode() is resulting in odd characters for control keys. For example I get "[" for left command, "%" for left arrow. Weirdness like that.

推荐答案

Keydown将为您提供按下的键的keyCode，无需任何修改。

Keydown will give you the keyCode of the key pressed, without any modifications.

$("#keypresser").keydown(function(e){
    var keycode = e.keyCode;

    var valid = 
        (keycode > 47 && keycode < 58)   || // number keys
        keycode == 32 || keycode == 13   || // spacebar & return key(s) (if you want to allow carriage returns)
        (keycode > 64 && keycode < 91)   || // letter keys
        (keycode > 95 && keycode < 112)  || // numpad keys
        (keycode > 185 && keycode < 193) || // ;=,-./` (in order)
        (keycode > 218 && keycode < 223);   // [\]' (in order)

    return valid;
});

只有数字键，字母键和空格键才会有与相关的密码代码String.fromCharCode 因为它使用Unicode值。

Only the number keys, letter keys, and spacebar will have keycodes correlating to String.fromCharCode as it uses Unicode values.

Keypress将是输入文本的charCode表示。请注意，如果由于按键没有打印文本，则不会触发此事件。

Keypress will be the charCode representation of the text entered. Note that this event won't fire if no text is "printed" as a result of the keypress.

$("#keypresser").keypress(function(e){
    var charcode = e.charCode;
    var char = String.fromCharCode(charcode);
    console.log(char);
});

http://jsfiddle.net/LZs2D/1/ 将演示这些如何工作。

http://jsfiddle.net/LZs2D/1/ Will demonstrate how these work.

KeyUp的行为与KeyDown类似。

KeyUp behaves similarly to KeyDown.

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