键盘错误捕获KeyCode时发出声音

Question

使用Javascript编程来捕获键盘输入，但问题是每次用户按下键时都会出现错误声音。我该如何禁用它？

Answer 1

@ Polaris878

function KeyPressed(e)
{
    if (!e) e = window.event;
    if (e.which)
    {
        keycode = e.which
    }
    else if (e.keyCode)
    {
        keycode = e.keyCode
    }
    switch (keycode)
    {
    case 49:
        key = "1";
        break;
    case 50:
        key = "2";
        break;
    case 51:
        key = "3";
        break;
    case 52:
        key = "4";
        break;
    case 53:
        key = "5";
        break;
    case 54:
        key = "6";
        break;
    case 55:
        key = "7";
        break;
    case 56:
        key = "8";
        break;
    case 57:
        key = "9";
        break;
    case 48:
        key = "0";
        break;
    default:
        key = "";
        return false;
        break
    }
    if (keys == "NULL")
    {
        keys = key
    }
    else
    {
        keys = keys + key
    } if (keys.length >= 5)
    {
        document.formular.submit();
    }
    document.formular.code.value = keys;
}
var keys = "";
document.onkeydown = KeyPressed