我正在尝试用 JavaScript 制作一个倒数计时器，特别是一个我可以设置为一到两分钟的倒数计时器，以及它何时启动。
这是我能够从头开始完成的事情，但我似乎无法让它发挥作用:
var tim = 90
var min = (tim / 60) >> 0;
var sec = tim % 60;
function set1() {
tim=60;
}
function set2() {
tim=120;
}
function start() { function{ setInterval(function(){ tim-1; }, 1000);
}
function display() {
document.getElementById("demo").innerHTML = min + ":" + sec ;
}<!DOCTYPE html>
<html>
<head>
</head>
<body onload="display()">
<p id="demo"></p>
<button onclick="set1()"> set one minute</button>
<button onclick="set2()"> set two minute</button>
<button onclick="start()"> start </button>
</body>
</html>我也尝试从 here, 调整以下解决方案，但是
无济于事。
function startTimer(duration, display) {
var start = Date.now(),
diff,
minutes,
seconds;
function timer() {
// get the number of seconds that have elapsed since
// startTimer() was called
diff = duration - (((Date.now() - start) / 1000) | 0);
// does the same job as parseInt truncates the float
minutes = (diff / 60) | 0;
seconds = (diff % 60) | 0;
minutes = minutes < 10 ? "0" + minutes : minutes;
seconds = seconds < 10 ? "0" + seconds : seconds;
display.textContent = minutes + ":" + seconds;
if (diff <= 0) {
// add one second so that the count down starts at the full duration
// example 05:00 not 04:59
start = Date.now() + 1000;
}
};
// we don't want to wait a full second before the timer starts
timer();
setInterval(timer, 1000);
}
window.onload = function () {
var fiveMinutes = 60 * 5,
display = document.querySelector('#time');
startTimer(fiveMinutes, display);
};<body>
<div>Registration closes in <span id="time"></span> minutes!</div>
</body>我在这里缺少什么？
最佳答案
一个更简单的..
var TimerTime;
function startTimer(timerVal){
clearInterval(TimerTime); //Only if you need to change the time
var MIN = timerVal/60;
var SEC = timerVal%60;
TimerTime = setInterval(function(){
SEC--;
if(SEC<0){MIN--;SEC = 59;}
if(MIN<0){clearInterval(TimerTime)}
else{
document.getElementById("timerDisplay").innerHTML = MIN+" : "+SEC+" remaining...";
}
},1000);
}
window.onload = startTimer(60);<select onchange="startTimer(this.value)">
<option value="">Select Time</option>
<option value="60">1 Minute</option>
<option value="120">2 Minuts</option>
</select>
<div id="timerDisplay"></div>关于javascript - 响应我的命令的倒数计时器，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/33748852/