JavaScript计时器
<!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>JavaScript计时器</title>
<style>
body {
padding: 40px;
margin: 0;
}
.timeTitle {
font-size: 28px;
line-height: 80px;
}
#timeNow {
color: #67c23a;
}
.btn {
display: inline-flex;
justify-content: center;
align-items: center;
line-height: 1;
height: 32px;
white-space: nowrap;
cursor: pointer;
color: #FFFFFF;
text-align: center;
box-sizing: border-box;
outline: none;
transition: .1s;
font-weight: 500;
user-select: none;
vertical-align: middle;
-webkit-appearance: none;
background-color: #409eff;
border: 1px solid #dcdfe6;
border-color: #409eff;
padding: 8px 15px;
font-size: 14px;
border-radius: 4px;
margin-right: 16px;
}
.btn:last-child {
margin-right: 0;
}
.btn:hover {
background-color: #79bbff;
border-color: #79bbff;
}
.warning {
background-color: #e6a23c;
border-color: #e6a23c;
}
.warning:hover {
background-color: #eebe77;
border-color: #eebe77;
}
.danger {
background-color: #f56c6c;
border-color: #f56c6c;
}
.danger:hover {
background-color: #f89898;
border-color: #f89898;
}
</style>
</head>
<body>
<div class="timeTitle">当前时间为:<span id="timeNow">00:00:00</span></div>
<button class="btn" id="timeBegin">计时开始</button>
<button class="btn warning " id="timeEnd">计时结束</button>
<button class="btn danger" id="timeClear">计时清除</button>
<script>
var timer = "";
var beginBtn = document.getElementById("timeBegin");
var endBtn = document.getElementById("timeEnd");
var clearBtn = document.getElementById("timeClear");
var beginNum = 0;
var min, second, millisecond;
min = second = millisecond = 0;
function time() {
millisecond += 50;
if (millisecond >= 1000) {
millisecond = 0
second += 1;
}
if (second >= 60) {
second = 0
min += 1;
}
counts = min + ':' + second + ':' + millisecond;
document.getElementById("timeNow").innerText = counts;
}
function BeginTime() {
beginBtn.onclick = function () {
if (beginNum > 0) {
return;
}
beginNum++;
timer = setInterval(time, 50);
}
}
function EndTime() {
endBtn.onclick = function () {
beginNum = 0;
clearInterval(timer);
}
}
function ClearTime() {
clearBtn.onclick = function () {
beginNum = 0;
clearInterval(timer);
document.getElementById("timeNow").innerHTML = "00:00:00";
}
}
BeginTime();
EndTime();
ClearTime()
</script>
</body>
</html>