jsbin.com demo
您将看到演示代码只是一个启动/停止/重置毫秒计数器.如果你想在时间上做出奇特的格式,那完全取决于你.这应该足以让你入门.
这是一个有趣的小项目.这就是我接近它的方式
var Stopwatch = function(elem, options) {
var timer = createTimer(),
startButton = createButton("start", start),
stopButton = createButton("stop", stop),
resetButton = createButton("reset", reset),
offset,
clock,
interval;
// default options
options = options || {};
options.delay = options.delay || 1;
// append elements
elem.appendChild(timer);
elem.appendChild(startButton);
elem.appendChild(stopButton);
elem.appendChild(resetButton);
// initialize
reset();
// private functions
function createTimer() {
return document.createElement("span");
}
function createButton(action, handler) {
var a = document.createElement("a");
a.href = "#" + action;
a.innerHTML = action;
a.addEventListener("click", function(event) {
handler();
event.preventDefault();
});
return a;
}
function start() {
if (!interval) {
offset = Date.now();
interval = setInterval(update, options.delay);
}
}
function stop() {
if (interval) {
clearInterval(interval);
interval = null;
}
}
function reset() {
clock = 0;
render();
}
function update() {
clock += delta();
render();
}
function render() {
timer.innerHTML = clock/1000;
}
function delta() {
var now = Date.now(),
d = now - offset;
offset = now;
return d;
}
// public API
this.start = start;
this.stop = stop;
this.reset = reset;
};
获取一些基本的HTML包装器
用法很简单
var elems = document.getElementsByClassName("stopwatch");
for (var i=0, len=elems.length; i
作为奖励,您还可以获得定时器的可编程API.这是一个用法示例
var elem = document.getElementById("my-stopwatch");
var timer = new Stopwatch(elem, {delay: 10});
// start the timer
timer.start();
// stop the timer
timer.stop();
// reset the timer
timer.reset();
jQuery插件
至于jQuery部分,一旦你有如上所述的良好代码组合,编写一个jQuery插件就是一个简单的模式
(function($) {
var Stopwatch = function(elem, options) {
// code from above...
};
$.fn.stopwatch = function(options) {
return this.each(function(idx, elem) {
new Stopwatch(elem, options);
});
};
})(jQuery);
jQuery插件用法
// all elements with class .stopwatch; default delay (1 ms)
$(".stopwatch").stopwatch();
// a specific element with id #my-stopwatch; custom delay (10 ms)
$("#my-stopwatch").stopwatch({delay: 10});
@Tigran如果用户重新启动计算机或刷新浏览器选项卡,计时器也将停止工作.这些不是"陷阱".除非有某种合理的无关要求,否则我不会编写代码来解决这些"问题". (5认同)
哇,很棒的工作.你应该得到500赏金. (4认同)
Legends..
8
如果您需要微秒精度使用:
performance.now ( - >浏览器支持)
var t0 = performance.now();
doSomething();
var t1 = performance.now();
console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.");
function doSomething(){
for(i=0;i<1000000;i++){var x = i*i;}
}
与JavaScript可用的其他计时数据(例如Date.now)不同,Performance.now()返回的时间戳不限于1毫秒的分辨率.相反,它们将时间表示为具有高达微秒精度的浮点数.
与Date.now()不同,Performance.now()返回的值总是以恒定速率增加,与系统时钟无关(可以手动调整或由NTP等软件调整).否则,performance.timing.navigationStart + performance.now()将大致等于Date.now().
对于日志记录,您可以使用
如果要测量操作所花费的时间(以毫秒为单位)并将其记录到控制台,请使用以下命令:
console.time('Search page');
doSomething();
console.timeEnd('Search page');
function doSomething(){
for(i=0;i<1000000;i++){var x = i*i;}
}
结果:
定时器名称:0.013ms
您可以更改不同操作的Timer-Name.
例:
var t0 = performance.now();
doSomething();
var t1 = performance.now();
console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.");
function doSomething(){
for(i=0;i<1000000;i++){var x = i*i;}
}
jsbin.com demo
您将看到演示代码只是一个启动/停止/重置毫秒计数器.如果你想在时间上做出奇特的格式,那完全取决于你.这应该足以让你入门.
这是一个有趣的小项目.这就是我接近它的方式
var Stopwatch = function(elem, options) {
var timer = createTimer(),
startButton = createButton("start", start),
stopButton = createButton("stop", stop),
resetButton = createButton("reset", reset),
offset,
clock,
interval;
// default options
options = options || {};
options.delay = options.delay || 1;
// append elements
elem.appendChild(timer);
elem.appendChild(startButton);
elem.appendChild(stopButton);
elem.appendChild(resetButton);
// initialize
reset();
// private functions
function createTimer() {
return document.createElement("span");
}
function createButton(action, handler) {
var a = document.createElement("a");
a.href = "#" + action;
a.innerHTML = action;
a.addEventListener("click", function(event) {
handler();
event.preventDefault();
});
return a;
}
function start() {
if (!interval) {
offset = Date.now();
interval = setInterval(update, options.delay);
}
}
function stop() {
if (interval) {
clearInterval(interval);
interval = null;
}
}
function reset() {
clock = 0;
render();
}
function update() {
clock += delta();
render();
}
function render() {
timer.innerHTML = clock/1000;
}
function delta() {
var now = Date.now(),
d = now - offset;
offset = now;
return d;
}
// public API
this.start = start;
this.stop = stop;
this.reset = reset;
};
获取一些基本的HTML包装器
<!-- create 3 stopwatches -->
<div class="stopwatch"></div>
<div class="stopwatch"></div>
<div class="stopwatch"></div>
用法很简单
var elems = document.getElementsByClassName("stopwatch");
for (var i=0, len=elems.length; i<len; i++) {
new Stopwatch(elems[i]);
}
作为奖励,您还可以获得定时器的可编程API.这是一个用法示例
var elem = document.getElementById("my-stopwatch");
var timer = new Stopwatch(elem, {delay: 10});
// start the timer
timer.start();
// stop the timer
timer.stop();
// reset the timer
timer.reset();
至于jQuery部分,一旦你有如上所述的良好代码组合,编写一个jQuery插件就是一个简单的模式
(function($) { var Stopwatch = function(elem, options) { // code from above... }; $.fn.stopwatch = function(options) { return this.each(function(idx, elem) { new Stopwatch(elem, options); }); }; })(jQuery);
jQuery插件用法
// all elements with class .stopwatch; default delay (1 ms) $(".stopwatch").stopwatch(); // a specific element with id #my-stopwatch; custom delay (10 ms) $("#my-stopwatch").stopwatch({delay: 10});
如果您需要微秒精度使用:
performance.now ( - >浏览器支持)
var t0 = performance.now();
doSomething();
var t1 = performance.now();
console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.");
function doSomething(){
for(i=0;i<1000000;i++){var x = i*i;}
}