keydown键盘事件回调函数触发两次是为什么?换成keyup也是一样的
按按钮,元素获得焦点,然后再按键盘,松开即触发keyup
<!DOCTYPE html>
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="js/jquery-3.3.1.min.js"></script>
</head>
<body>
<input id="input1" type="button" value="keyup" onkeyup="keyup()" >
<input id="input2" type="button" value="keyup2" onkeyup="keyup2()" >
<input id="input3" type="button" value="keyup3" onkeyup="keyup3()" >
</body>
<script>
$(function () {
$("#input1").keyup(function () {
$("#input1").css("color","red");
});
$("#input2").keyup(function () {
$("#input2").css("color","pink");
});
$("#input3").keyup(function () {
$("#input3").css("color","blue");
});
});
</script>