Question

我有一个简单的测验应用程序，我希望在页面顶部显示一个漂亮的计时器/时钟，向用户显示他们需要多长时间。（如果我能以某种方式向他们展示总测验时间的计时器，也可以为这个问题时间显示第二个计时器，这个计时器甚至会更冷，但是一旦我有一个计时器工作，我应该能够弄清楚自己该如何做。 / p>

我的问题是：

使用JQuery显示简单定时器/时钟的简单方法是什么？（直接JS也行不通）我知道如何检查时间，但是如何增加秒数呢？

我自己的搜索引导我继续使用JQuery插件（我想自己推出）以及“事件计时器”，这些都不是我想要的......

Answer 1

您正在寻找setInterval函数，该函数每 x 毫秒运行一个函数。

例如：

var start = new Date;

setInterval(function() {
    $('.Timer').text((new Date - start) / 1000 + " Seconds");
}, 1000);

Answer 2

SLaks建议的setInterval正是我制作计时器所需要的。（谢谢你的伴侣！）

使用setInterval和this great blog post我最终创建了以下函数来在我的“box_header”div中显示一个计时器。我希望这可以帮助其他有类似要求的人！

 function get_elapsed_time_string(total_seconds) {
  function pretty_time_string(num) {
    return ( num < 10 ? "0" : "" ) + num;
  }

  var hours = Math.floor(total_seconds / 3600);
  total_seconds = total_seconds % 3600;

  var minutes = Math.floor(total_seconds / 60);
  total_seconds = total_seconds % 60;

  var seconds = Math.floor(total_seconds);

  // Pad the minutes and seconds with leading zeros, if required
  hours = pretty_time_string(hours);
  minutes = pretty_time_string(minutes);
  seconds = pretty_time_string(seconds);

  // Compose the string for display
  var currentTimeString = hours + ":" + minutes + ":" + seconds;

  return currentTimeString;
}

var elapsed_seconds = 0;
setInterval(function() {
  elapsed_seconds = elapsed_seconds + 1;
  $('#box_header').text(get_elapsed_time_string(elapsed_seconds));
}, 1000);

Answer 3

################## JQuery (use API) #################   
 $(document).ready(function(){
         function getdate(){
                var today = new Date();
            var h = today.getHours();
            var m = today.getMinutes();
            var s = today.getSeconds();
             if(s<10){
                 s = "0"+s;
             }
             if (m < 10) {
                m = "0" + m;
            }
            $("h1").text(h+" : "+m+" : "+s);
             setTimeout(function(){getdate()}, 500);
            }

        $("button").click(getdate);
    });

################## HTML ###################
<button>start clock</button>
<h1></h1>

Answer 4

这两个世界的优点怎么样？我将答案与OP的格式结合起来。

function pretty_time_string(num) {
    return ( num < 10 ? "0" : "" ) + num;
  }

var start = new Date;    

setInterval(function() {
  var total_seconds = (new Date - start) / 1000;   

  var hours = Math.floor(total_seconds / 3600);
  total_seconds = total_seconds % 3600;

  var minutes = Math.floor(total_seconds / 60);
  total_seconds = total_seconds % 60;

  var seconds = Math.floor(total_seconds);

  hours = pretty_time_string(hours);
  minutes = pretty_time_string(minutes);
  seconds = pretty_time_string(seconds);

  var currentTimeString = hours + ":" + minutes + ":" + seconds;

  $('.timer').text(currentTimeString);
}, 1000);

Answer 5

24小时制：

setInterval(function(){

        var currentTime = new Date();
        var hours = currentTime.getHours();
        var minutes = currentTime.getMinutes();
        var seconds = currentTime.getSeconds();

        // Add leading zeros
        minutes = (minutes < 10 ? "0" : "") + minutes;
        seconds = (seconds < 10 ? "0" : "") + seconds;
        hours = (hours < 10 ? "0" : "") + hours;

        // Compose the string for display
        var currentTimeString = hours + ":" + minutes + ":" + seconds;
        $(".clock").html(currentTimeString);

},1000);

＆＃13;

// 24 hour clock  
setInterval(function() {

  var currentTime = new Date();
  var hours = currentTime.getHours();
  var minutes = currentTime.getMinutes();
  var seconds = currentTime.getSeconds();

  // Add leading zeros
  hours = (hours < 10 ? "0" : "") + hours;
  minutes = (minutes < 10 ? "0" : "") + minutes;
  seconds = (seconds < 10 ? "0" : "") + seconds;

  // Compose the string for display
  var currentTimeString = hours + ":" + minutes + ":" + seconds;
  $(".clock").html(currentTimeString);

}, 1000);

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="clock"></div>

＆＃13;

Answer 6

如果你可以在Moment.js（伟大的库）中使用jQuery，那就是这样的：

var crClockInit1 = null;
var crClockInterval = null;
function crInitClock() {
    crClockInit1 = setInterval(function() {
        if (moment().format("SSS") <= 40) {
            clearInterval(crClockInit1);
            crStartClockNow();
        }
    }, 30);
}

function crStartClockNow() {
    crClockInterval = setInterval(function() {
        $('#clock').html(moment().format('D. MMMM YYYY H:mm:ss'));
    }, 1000);
}

使用crInitClock()开始时钟初始化。它以这种方式完成同步秒。如果没有同步，你将在半秒内启动1秒计时器，并且在实时之后会延迟半秒。

Answer 7

var eventdate = new Date("January 01, 2014 00:00:00");

function toSt(n) {
 s=""
 if(n<10) s+="0"
 return s+n.toString();
}

function countdown() {
 cl=document.clock;
 d=new Date();
 count=Math.floor((eventdate.getTime()-d.getTime())/1000);
 if(count<=0)
   {cl.days.value ="----";
    cl.hours.value="--";
    cl.mins.value="--";
    cl.secs.value="--";
    return;
  }
 cl.secs.value=toSt(count%60);
 count=Math.floor(count/60);
 cl.mins.value=toSt(count%60);
 count=Math.floor(count/60);
 cl.hours.value=toSt(count%24);
 count=Math.floor(count/24);
 cl.days.value=count;    

 setTimeout("countdown()",500);
}

你好，我有一个类似的任务，涉及创建一个Javascript倒计时时钟。这是我使用的代码。将上面的代码插入＆lt; script language =“Javascript”＆gt;＆lt; / script＆gt;标签。请记住，如果你没有显示时钟的html，那么只有这个javascript不会做太多。我会留下给你写的HTML。按照您的意愿设计时钟。

Answer 8

    var timeInterval = 5;
    var blinkTime = 1;
    var open_signal = 'signal1';
    var total_signal = 1;

    $(document).ready(function () {
        for (var i = 1; i <= total_signal; i++) {
            var timer = (i == 1) ? timeInterval : (timeInterval * (i - 1));

            var str_html = '<div id="signal' + i + '">' +
                           '<span class="float_left">Signal ' + i + ' : </span>' +
                           '<div class="red float_left"></div>' +
                           '<div class="yellow float_left"></div>' +
                           '<div class="green float_left"></div>' +
                           '<div class="timer float_left">' + timer + '</div>' +
                           '<div style="clear: both;"></div>' +
                           '</div><div class="div_separate"></div>';

            $('.div_demo').append(str_html);
        }

        $('.div_demo .green').eq(0).css('background-color', 'green');
        $('.div_demo .red').css('background-color', 'red');
        $('.div_demo .red').eq(0).css('background-color', 'white');

        setInterval(function () {
            manageSignals();
        }, 1000);
    });

    function manageSignals() {
        var obj_timer = {};

        var temp_i = parseInt(open_signal.substr(6));
        if ($('#' + open_signal + ' .timer').html() == '0')
            open_signal = (temp_i == total_signal) ? 'signal1' : 'signal' + (temp_i + 1);

        for (var i = 1; i <= total_signal; i++) {
            var next_signal = (i == total_signal) ? 'signal1' : 'signal' + (i + 1);

            obj_timer['signal' + i] = parseInt($('#signal' + i + ' .timer').html()) - 1;

            if (obj_timer['signal' + i] == -1 && open_signal == next_signal && total_signal!=1) {
                obj_timer['signal' + i] = (timeInterval * (total_signal - 1)) - 1;

                $('#signal' + i + ' .red').css('background-color', 'red');
                $('#signal' + i + ' .yellow').css('background-color', 'white');
            }
            else if (obj_timer['signal' + i] == -1 && open_signal == 'signal' + i) {
                obj_timer['signal' + i] = (timeInterval - 1);

                $('#signal' + i + ' .red').css('background-color', 'white');
                $('#signal' + i + ' .yellow').css('background-color', 'white');
                $('#signal' + i + ' .green').css('background-color', 'green');
            }
            else if (obj_timer['signal' + i] == blinkTime && open_signal == 'signal' + i) {
                $('#signal' + i + ' .yellow').css('background-color', 'yellow');
                $('#signal' + i + ' .green').css('background-color', 'white');
            }

            $('#signal' + i + ' .timer').html(obj_timer['signal' + i]);
        }
    }
</script>

Answer 9

Here's @SLaks answer, but in pure ES6 JavaScript.

var start = new Date,
  $timer = document.querySelector('.Timer');

setInterval(function(timestamp) {
    $timer.innerText = `${timestamp - start) / 1000} Seconds`;
}, 1000);

Answer 10

只需使用@Uday答案代码并建立hr：mm的反向时钟

只是在玩，所以考虑是否有人会需要这个，所以在评论中分享小提琴（Dnt知道为什么stackover流不允许我在此处粘贴链接）

如何创建JQuery时钟/计时器

11 个答案: