公司主营业务是体育赛事为主的；尤其是足球赛事。现正值2016法国欧洲杯；之前忙于做欧洲杯专题没时间总结。现分享一个工作中需求带来的经历。
需求是：从现在开始倒计时欧洲杯还有多久开赛；当开赛之后开始计算已经开赛了几天及计算当前是小组赛还是1/8决赛,1/4决赛,半决赛,决赛。
废话不多说，直接上代码:
var cdInterval, dateInterval;
//此方法为倒计时欧洲杯开赛时间，原理是用开赛时间的毫秒数减去当前毫秒数然后根据每天，小时，分，秒的毫秒数向下取整
function countDown(){
var agent = navigator.userAgent, startTime;
if(agent.indexOf('Trident') > -1 || agent.indexOf('Edge') > -1) { // ie,因为IE不支持new Date('xxx')创建Date对象的时候传入的时间参数，所以这里使用
//setUTCFullYear和setUTCHours，再getTime()等到当前毫秒数
var euroDate = new Date();
euroDate.setUTCFullYear('2016','05','10');//月份是从0-11的
euroDate.setUTCHours('4','0','0','0');
startTime = euroDate;
} else {
startTime = new Date("2016 06 10 12:00:00");
}
var nowTime = new Date(), distanceTime
,startServer = startTime.getTime(), nowServer = nowTime.getTime();
distanceTime = startServer - nowServer; // 一天的豪秒数86400000 一个小时的毫秒数3600000 一分钟的毫秒数 60000 一秒钟的毫秒数 1000
var d_date, d_hour, d_min,d_second;
if(distanceTime > 0) {
d_date = Math.floor(distanceTime/86400000); //计算还有几天
distanceTime -= d_date*86400000; //减去天数毫秒数计算下面的 小时数，分钟数，秒数
d_hour = Math.floor(distanceTime/3600000);//计算小时
distanceTime -= d_hour*3600000;//减去当前小时的毫秒数
d_min = Math.floor(distanceTime/60000);//计算分
distanceTime -= d_min*60000;//减去当前分的毫秒数
d_second = Math.floor(distanceTime/1000);//计算秒
distanceTime -= d_second*1000;//减去当前秒的毫秒数
if(d_date < 10) {
d_date = '0' + d_date;
}
if(d_hour < 10) {
d_hour = '0' + d_hour;
}
if(d_min < 10) {
d_min = '0' + d_min;
}
if(d_second < 10) {
d_second = '0' + d_second;
}
document.getElementsByClassName('icon-time')[0].innerHTML = d_date; document.getElementsByClassName('icon-time')[1].innerHTML = d_hour; document.getELementsByClassName('icon-time')[2].innerHTML = d_min; document.getElementsByClassName('icon-time')[3].innerHTML = d_second; } else {
clearInterval(cdInterval);
clearInterval(dateInterval);
$('.icon-time:not(:first)').remove(); $('div.time span').each(function(index, item) {
if(index !== 0 && index !== 1) {
$(this).remove();
}
});
backwardDays()
dateInterval = setInterval(backwardDays, 10000);
}
}
//天数，原理为用当前毫秒数减去开赛时候的毫秒数计算出已经开赛了几天
function backwardDays(){
var dataAgent = navigator.userAgent;
var groupGameStart = 0,groupGameEnd = 0,eighthGameStart = 0,eighthGameEnd = 0,fourGameStart = 0,fourGameEnd = 0,halfGameStart = 0, halfGameEnd = 0,
finalGame = 0,endGame = 0;
var dist_day = '', day = '',now_day = '';
//计算赛事时间
if(dataAgent.indexOf('Trident') > -1 || dataAgent.indexOf('Edge') > -1) { //同上ie不支持new Date('xx')带参数
var groupDayStart = new Date();
var groupDayEnd = groupDayStart,
eighthDayStart = groupDayStart, eighthDayEnd = groupDayStart,
fourDayStart = groupDayStart,fourDayEnd = groupDayStart,
halfDayStart = groupDayStart,halfDayEnd = groupDayStart,
finalDayStart = groupDayStart,finalDayEnd = groupDayStart;
//小组赛
groupDayStart.setUTCFullYear('2016','05','10'); groupDayStart.setUTCHours('4','0','0','0');
groupGameStart = groupDayStart.getTime();
groupDayEnd.setUTCFullYear('2016','05','24');groupDayEnd.setUTCHours('4','0','0','0');
groupGameEnd = groupDayEnd.getTime();
//1/8决赛
eighthDayStart.setUTCFullYear('2016','05','25'); eighthDayStart.setUTCHours('4','0','0','0');
eighthGameStart = eighthDayStart.getTime();
eighthDayEnd.setUTCFullYear('2016','05','28');eighthDayEnd.setUTCHours('4','0','0','0');
eighthGameEnd = eighthDayEnd.getTime();
//1/4决赛
fourDayStart.setUTCFullYear('2016','06','01'); fourDayStart.setUTCHours('4','0','0','0');
fourGameStart = fourDayStart.getTime();
fourDayEnd.setUTCFullYear('2016','06','04');fourDayEnd.setUTCHours('4','0','0','0');
fourGameEnd = fourDayEnd.getTime();
//半决赛
halfDayStart.setUTCFullYear('2016','06','07'); halfDayStart.setUTCHours('4','0','0','0');
halfGameStart = halfDayStart.getTime();
halfDayEnd.setUTCFullYear('2016','06','08');halfDayEnd.setUTCHours('4','0','0','0');
halfGameEnd = halfDayEnd.getTime();
//决赛
finalDayStart.setUTCFullYear('2016','06','11'); finalDayStart.setUTCHours('4','0','0','0');
finalGame = finalDayStart.getTime();
finalDayEnd.setUTCFullYear('2016','06','11');finalDayEnd.setUTCHours('15','59','0','0');
endGame = finalDayEnd.getTime(); } else {
groupGameStart = new Date("2016 06 10 12:00").getTime();
groupGameEnd = new Date("2016 06 24 12:00").getTime(),//小组赛结束
eighthGameStart = new Date("2016 06 25 12:00").getTime(), // 1/8决赛开始
eighthGameEnd = new Date("2016 06 28 12:00").getTime(), // 1/8决赛结束
fourGameStart = new Date("2016 07 01 12:00").getTime(), // 1/4决赛开始
fourGameEnd = new Date("2016 07 04 12:00").getTime(), // 1/4决赛结束
halfGameStart = new Date("2016 07 07 12:00").getTime(), //半决赛开始
halfGameEnd = new Date("2016 07 08 12:00").getTime(), //半决赛结束
finalGame = new Date("2016 07 11 12:00").getTime(), // 决赛
endGame = new Date("2016 07 11 23:59").getTime(); // 欧洲杯结束
} var currentTime = new Date().getTime();//当前时间
//第几天
now_day = (currentTime - groupGameStart)/86400000;
dist_day = Math.floor((currentTime - groupGameStart)/86400000);
if(now_day > dist_day) {//如果计算出的当前天数大于向下取整的天数，则要加1
day = dist_day + 1;
} else {
day = dist_day
} if(day === 0) {//day等于0的时候表示已经开赛，所以计算为第一天
day = 1;
}
if(day < 10) {
day = '0' + day;
}
$('.icon-time:eq(0)').text(day);
//根据时间范围算出赛事范围
if(currentTime >= groupGameStart && currentTime <= groupGameEnd) {//小组赛
$("em.gameType").text($('#xzs').val());
} else if(currentTime >= eighthGameStart && currentTime <= eighthGameEnd) {// 1/8 决赛
$("em.gameType").text("1/8"+$('#jsi').val());
} else if(currentTime >= fourGameStart && currentTime <= fourGameEnd) {// 1/4决赛
$("em.gameType").text("1/4"+$('#jsi').val());
} else if(currentTime >= halfGameStart && currentTime <= halfGameEnd) {// 半决赛
$("em.gameType").text($('#bjs').val());
} else if(currentTime >= finalGame && currentTime <= endGame) { //决赛
$("em.gameType").text($('#jsi').val());
} else {
$("em.gameType").text("");
} if(currentTime >= endGame) {
clearInterval(dateInterval);
}
}
$(function(){
clearInterval(cdInterval);
cdInterval = setInterval(countDown,1000);
});