检测 CAPS LOCK 何时打开

Question

我有此代码用于将按键添加到密码中。如果 capslock 开启，它将触发。我从How do you tell if caps lock is on using JavaScript?得到它

$("input[type='password']").keypress(function(e) {

    var $warn = $(this).next(".capsWarn"); // handle the warning mssg
    var kc = e.which; //get keycode
    var isUp = (kc >= 65 && kc <= 90) ? true : false; // uppercase
    var isLow = (kc >= 97 && kc <= 122) ? true : false; // lowercase
    // event.shiftKey does not seem to be normalized by jQuery(?) for IE8-
    var isShift = ( e.shiftKey ) ? e.shiftKey : ( (kc == 16) ? true : false ); // shift is pressed

    // uppercase w/out shift or lowercase with shift == caps lock
    if ( (isUp && !isShift) || (isLow && isShift) ) {
        $warn.show();
    } else {
        $warn.hide();
    }

}).after(capLock());
function capLock(e){
 alert('CAPSLOCK is ON');
}

原始代码中有span中的消息：

...}).after(<span class='capsWarn error' style='display:none;'>CAPSLOCK is ON</span>);

我希望它是一条警报消息，但它没有按我预期的那样运行。加载时它应该提醒消息，但即使 capslock 是 on 它也不显示提醒。

如何让它检测密钥并显示警报？

Answer 1

$("input[type='password']").keypress(function(e) {

    var $warn = $(this).next(".capsWarn");//can be removed since you are just using alert
    var kc = e.which; //get keycode
    var isUp = (kc >= 65 && kc <= 90) ? true : false; // uppercase
    var isLow = (kc >= 97 && kc <= 122) ? true : false; // lowercase
    // event.shiftKey does not seem to be normalized by jQuery(?) for IE8-
    var isShift = ( e.shiftKey ) ? e.shiftKey : ( (kc == 16) ? true : false ); // shift is pressed

    // uppercase w/out shift or lowercase with shift == caps lock
    if ( (isUp && !isShift) || (isLow && isShift) ) {
        capLock(); // alerts "CAPSLOCK is ON"
    }

});
function capLock() {
 alert('CAPSLOCK is ON');
}