当做验证码登录时，发送验证码后为了得到更好的体验效果，input选框中应加上倒计时：
- 代码如下
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<div>
<button id="code" class="btn btn-default" onclick="getCode();">获取校验码</button>
</div>
</body>
</html>
<script src="/js/jquery.min.js"></script>
var i;
function getCode() {
//点击按钮后设置时间内不能点击
$('#code').attr({"disabled":"disabled"});
//调用定时任务
i = self.setInterval("countdown()",1000);
}
var int = 60;
function countdown() {
document.getElementById("code").innerHTML = int + "秒后重新发送";
int--;
if(int<0){
//清除定时任务
i=window.clearInterval(i);
int = 10;
$("#code").removeAttr("disabled").html("重新获取验证码");
}
}
</script>