javascript - 使用 shift 修饰符从键码中获取键字符(值)

Question

我很幸运地找到了 String.fromCharCode()。它对我帮助很大。但是，我注意到它没有考虑到 shift 修饰符。我知道 event.shiftKey 属性并使用它，但现在我需要获取考虑到 shift 键修饰符的键值(例如:“A”或“a”)。起初我使用 String.toLowerCase().. 但我忽略了数字键，举个例子:“5”(不带 shift)和“%”(带 shift)。我需要在我的程序中区分两者。获取键字符值的简单方法是什么？

Answer 1

这种蛮力技术不是最漂亮的，但它似乎有效。我正在寻找相同的功能。

function mapKeyPressToActualCharacter(isShiftKey, characterCode) {
    if ( characterCode === 27 || characterCode === 8 || characterCode === 9 || characterCode === 20 || characterCode === 16 || characterCode === 17 || characterCode === 91 || characterCode === 13 || characterCode === 92 || characterCode === 18 ) {
        return false;
    }
    if (typeof isShiftKey != "boolean" || typeof characterCode != "number") {
        return false;
    }
    var characterMap = [];
    characterMap[192] = "~";
    characterMap[49] = "!";
    characterMap[50] = "@";
    characterMap[51] = "#";
    characterMap[52] = "$";
    characterMap[53] = "%";
    characterMap[54] = "^";
    characterMap[55] = "&";
    characterMap[56] = "*";
    characterMap[57] = "(";
    characterMap[48] = ")";
    characterMap[109] = "_";
    characterMap[107] = "+";
    characterMap[219] = "{";
    characterMap[221] = "}";
    characterMap[220] = "|";
    characterMap[59] = ":";
    characterMap[222] = "\"";
    characterMap[188] = "<";
    characterMap[190] = ">";
    characterMap[191] = "?";
    characterMap[32] = " ";
    var character = "";
    if (isShiftKey) {
        if ( characterCode >= 65 && characterCode <= 90 ) {
            character = String.fromCharCode(characterCode);
        } else {
            character = characterMap[characterCode];
        }
    } else {
        if ( characterCode >= 65 && characterCode <= 90 ) {
            character = String.fromCharCode(characterCode).toLowerCase();
        } else {
            character = String.fromCharCode(characterCode);
        }
    }
    return character;
}