我想使用一个简单的倒计时计时器,从函数运行开始倒数30秒,最终结束于0。不要显示毫秒。如何编写代码?
我想使用一个简单的倒计时计时器,从函数运行开始倒数30秒,最终结束于0。不要显示毫秒。如何编写代码?
var count=30;
var counter=setInterval(timer, 1000); //1000 will run it every 1 second
function timer()
{
count=count-1;
if (count <= 0)
{
clearInterval(counter);
//counter ended, do something here
return;
}
//Do code for showing the number of seconds here
}
为了使定时器代码出现在段落(或页面任何其他位置),只需放置以下行:
<span id="timer"></span>
在你想让秒数出现的地方插入以下行,然后将此行插入到你的 timer()
函数中,使其看起来像这样:
function timer()
{
count=count-1;
if (count <= 0)
{
clearInterval(counter);
return;
}
document.getElementById("timer").innerHTML=count + " secs"; // watch for spelling
}
我之前写了这个脚本:
使用方法:
var myCounter = new Countdown({
seconds:5, // number of seconds to count down
onUpdateStatus: function(sec){console.log(sec);}, // callback for each second
onCounterEnd: function(){ alert('counter ended!');} // final action
});
myCounter.start();
function Countdown(options) {
var timer,
instance = this,
seconds = options.seconds || 10,
updateStatus = options.onUpdateStatus || function () {},
counterEnd = options.onCounterEnd || function () {};
function decrementCounter() {
updateStatus(seconds);
if (seconds === 0) {
counterEnd();
instance.stop();
}
seconds--;
}
this.start = function () {
clearInterval(timer);
timer = 0;
seconds = options.seconds;
timer = setInterval(decrementCounter, 1000);
};
this.stop = function () {
clearInterval(timer);
};
}
myCounter.stop();
- R3tep目前为止,答案似乎都是基于代码立即执行的。如果你设置一个1000毫秒的计时器,实际上会是大约1008毫秒。
下面是应该这样做的方法:
function timer(time,update,complete) {
var start = new Date().getTime();
var interval = setInterval(function() {
var now = time-(new Date().getTime()-start);
if( now <= 0) {
clearInterval(interval);
complete();
}
else update(Math.floor(now/1000));
},100); // the smaller this number, the more accurate the timer will be
}
使用时,请调用:
timer(
5000, // milliseconds
function(timeleft) { // called every step to update the visible countdown
document.getElementById('timer').innerHTML = timeleft+" second(s)";
},
function() { // what to do after
alert("Timer complete!");
}
);
如果有人需要分钟和秒钟的计时器,这里有另一个可用的:
var mins = 10; //Set the number of minutes you need
var secs = mins * 60;
var currentSeconds = 0;
var currentMinutes = 0;
/*
* The following line has been commented out due to a suggestion left in the comments. The line below it has not been tested.
* setTimeout('Decrement()',1000);
*/
setTimeout(Decrement,1000);
function Decrement() {
currentMinutes = Math.floor(secs / 60);
currentSeconds = secs % 60;
if(currentSeconds <= 9) currentSeconds = "0" + currentSeconds;
secs--;
document.getElementById("timerText").innerHTML = currentMinutes + ":" + currentSeconds; //Set the element id you need the time put into.
if(secs !== -1) setTimeout('Decrement()',1000);
}
setTimeout(Decrement, 1000)
。http://stackoverflow.com/questions/6232574/is-it-bad-practice-to-pass-a-string-to-settimeout-if-yes-why - Scottux刚刚修改了@ClickUpvote的回答:
你可以使用IIFE(立即调用函数表达式)和递归使它更容易一些:
var i = 5; //set the countdown
(function timer(){
if (--i < 0) return;
setTimeout(function(){
console.log(i + ' secs'); //do stuff here
timer();
}, 1000);
})();
var i = 5;
(function timer(){
if (--i < 0) return;
setTimeout(function(){
document.getElementsByTagName('h1')[0].innerHTML = i + ' secs';
timer();
}, 1000);
})();
<h1>5 secs</h1>
// Javascript Countdown
// Version 1.01 6/7/07 (1/20/2000)
// by TDavid at http://www.tdscripts.com/
var now = new Date();
var theevent = new Date("Sep 29 2007 00:00:01");
var seconds = (theevent - now) / 1000;
var minutes = seconds / 60;
var hours = minutes / 60;
var days = hours / 24;
ID = window.setTimeout("update();", 1000);
function update() {
now = new Date();
seconds = (theevent - now) / 1000;
seconds = Math.round(seconds);
minutes = seconds / 60;
minutes = Math.round(minutes);
hours = minutes / 60;
hours = Math.round(hours);
days = hours / 24;
days = Math.round(days);
document.form1.days.value = days;
document.form1.hours.value = hours;
document.form1.minutes.value = minutes;
document.form1.seconds.value = seconds;
ID = window.setTimeout("update();", 1000);
}
<p><font face="Arial" size="3">Countdown To January 31, 2000, at 12:00: </font>
</p>
<form name="form1">
<p>Days
<input type="text" name="days" value="0" size="3">Hours
<input type="text" name="hours" value="0" size="4">Minutes
<input type="text" name="minutes" value="0" size="7">Seconds
<input type="text" name="seconds" value="0" size="7">
</p>
</form>
Math.floor
而不是Math.round
。 - corbacho进一步扩展接受的答案,您的计算机进入睡眠等可能会延迟计时器的工作。您可以以稍微牺牲一些处理能力为代价获得真正的时间。这将提供真正剩余时间。
<span id="timer"></span>
<script>
var now = new Date();
var timeup = now.setSeconds(now.getSeconds() + 30);
//var timeup = now.setHours(now.getHours() + 1);
var counter = setInterval(timer, 1000);
function timer() {
now = new Date();
count = Math.round((timeup - now)/1000);
if (now > timeup) {
window.location = "/logout"; //or somethin'
clearInterval(counter);
return;
}
var seconds = Math.floor((count%60));
var minutes = Math.floor((count/60) % 60);
document.getElementById("timer").innerHTML = minutes + ":" + seconds;
}
</script>
https://caniuse.com/#search=requestAnimationFrame
/* Seconds to (STRING)HH:MM:SS.MS ------------------------*/
/* This time format is compatible with FFMPEG ------------*/
function secToTimer(sec){
const o = new Date(0), p = new Date(sec * 1000)
return new Date(p.getTime()-o.getTime()).toString().split(" ")[4] + "." + p.getMilliseconds()
}
/* Countdown loop ----------------------------------------*/
let job, origin = new Date().getTime()
const timer = () => {
job = requestAnimationFrame(timer)
OUT.textContent = secToTimer((new Date().getTime() - origin) / 1000)
}
/* Start looping -----------------------------------------*/
requestAnimationFrame(timer)
/* Stop looping ------------------------------------------*/
// cancelAnimationFrame(job)
/* Reset the start date ----------------------------------*/
// origin = new Date().getTime()
span {font-size:4rem}
<span id="OUT"></span>
<br>
<button onclick="origin = new Date().getTime()">RESET</button>
<button onclick="requestAnimationFrame(timer)">RESTART</button>
<button onclick="cancelAnimationFrame(job)">STOP</button>
我的解决方案适用于MySQL日期时间格式,并提供回调函数。在完成时。 免责声明:仅适用于分钟和秒,因为这是我所需的。
jQuery.fn.countDownTimer = function(futureDate, callback){
if(!futureDate){
throw 'Invalid date!';
}
var currentTs = +new Date();
var futureDateTs = +new Date(futureDate);
if(futureDateTs <= currentTs){
throw 'Invalid date!';
}
var diff = Math.round((futureDateTs - currentTs) / 1000);
var that = this;
(function countdownLoop(){
// Get hours/minutes from timestamp
var m = Math.floor(diff % 3600 / 60);
var s = Math.floor(diff % 3600 % 60);
var text = zeroPad(m, 2) + ':' + zeroPad(s, 2);
$(that).text(text);
if(diff <= 0){
typeof callback === 'function' ? callback.call(that) : void(0);
return;
}
diff--;
setTimeout(countdownLoop, 1000);
})();
function zeroPad(num, places) {
var zero = places - num.toString().length + 1;
return Array(+(zero > 0 && zero)).join("0") + num;
}
}
// $('.heading').countDownTimer('2018-04-02 16:00:59', function(){ // on complete})
var hr = 0;
var min = 0;
var sec = 0;
var count = 0;
var flag = false;
function start(){
flag = true;
stopwatch();
}
function stop(){
flag = false;
}
function reset(){
flag = false;
hr = 0;
min = 0;
sec = 0;
count = 0;
document.getElementById("hr").innerHTML = "00";
document.getElementById("min").innerHTML = "00";
document.getElementById("sec").innerHTML = "00";
document.getElementById("count").innerHTML = "00";
}
function stopwatch(){
if(flag == true){
count = count + 1;
setTimeout( 'stopwatch()', 10);
if(count ==100){
count =0;
sec = sec +1;
}
}
if(sec ==60){
min = min +1 ;
sec = 0;
}
if(min == 60){
hr = hr +1 ;
min = 0;
sec = 0;
}
var hrs = hr;
var mins = min;
var secs = sec;
if(hr<10){
hrs ="0" + hr;
}
if(min<10){
mins ="0" + min;
}
if(sec<10){
secs ="0" + sec;
}
document.getElementById("hr").innerHTML = hrs;
document.getElementById("min").innerHTML = mins;
document.getElementById("sec").innerHTML = secs;
document.getElementById("count").innerHTML = count;
}