JS实现秒表 

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>秒表的实现</title>
        <style type="text/css">
            #div1{
                width: 300px;
                height: 400px;
                background-color: gray;
                margin: 100px auto;
                text-align: center;
            }
            #count{
                width: 200px;
                height: 150px;
                line-height: 150px;
                margin: auto;
                font-size: 40px;
            }
            #div1 input{
                width: 150px;
                height: 40px;
                background-color: yellow;
                font-size: 25px;
                margin-top: 20px;
            }
        </style>
    </head>
    <body>
        <div id="div1">
            <div id="count">
                <span id="id_H">00</span>:
                <span id="id_M">00</span>:
                <span id="id_S">00</span>
            </div>
            <input id="start" type="button" value="开始">
            <input id="pause" type="button" value="暂停">
            <input id="stop" type="button" value="停止">
        </div>
        <script type="text/javascript">
            //将查找标签节点的操作进行简化/封装
            function $(id){
                return document.getElementById(id);
            }
            window.onload = function(){
                //点击开始计数
                var count = 0;//开始计数以后，累加的总秒数
                var timer = null;
                $("start").onclick = function(){
                    timer = setInterval(function(){
                        count++;
                        //需要改变页面上时分秒的值
                        $("id_S").innerHTML = showNum(count % 60);
                        $("id_M").innerHTML = showNum(parseInt(count / 60) % 60);
                        $("id_H").innerHTML = showNum(parseInt(count / 3600));
                        
                    },1000);
                }
                //暂停
                $("pause").onclick = function(){
                    //取消定时器
                    clearInterval(timer);
                }
                
                //停止 停止计数,数据清零<1>数据清理<2>页面展示数据清理
                $("stop").onclick = function(){
                    //取消定时器
                    clearInterval(timer);
                    //数据清理
                    count = 0;
                    //页面数据清理
                    $("id_S").innerHTML = "00";
                    $("id_M").innerHTML = "00";
                    $("id_H").innerHTML = "00";
                }
            }
                
            //处理单个数字
            function showNum(num){
                if(num<10){
                    return "0" + num;
                }else{
                    return num;
                }
            }
        </script>
    </body>
</html>

 

posted @ 2020-11-19 09:29  憬荃  阅读(301)  评论(0)    收藏  举报