if (wx.getStorageSync('timeLength')) {
console.log('已输入生产日期')
that.setData({
timeLength: wx.getStorageSync('timeLength')
})


var time = that.data.timeLength
var timer = setInterval(function () {
time--
var day = (Math.floor(time / 60 / 60 / 24) > 0) ? Math.floor(time / 60 / 60 / 24) : 0
var hour = Math.floor((time - Math.floor(time / 60 / 60 / 24) * 60 * 60 * 24) / 60 / 60)
var minute = Math.floor((time - Math.floor(time / 60 / 60 / 24) * 60 * 60 * 24 - Math.floor((time - Math.floor(time / 60 / 60 / 24) * 60 * 60 * 24) / 60 / 60) * 60 * 60) / 60)
var second = Math.floor(time - Math.floor(time / 60 / 60 / 24) * 60 * 60 * 24 - Math.floor((time - Math.floor(time / 60 / 60 / 24) * 60 * 60 * 24) / 60 / 60) * 60 * 60 - Math.floor((time - Math.floor(time / 60 / 60 / 24) * 60 * 60 * 24 - Math.floor((time - Math.floor(time / 60 / 60 / 24) * 60 * 60 * 24) / 60 / 60) * 60 * 60) / 60) * 60)


if (that.data.dayNum <= 0) {
that.setData({
dayNum: 0
})
}
if (that.data.hourNum <= 0) {
that.setData({
hourNum: 0
})
}
if (that.data.minuteNum <= 0) {
that.setData({
minuteNum: 0
})
}
if (that.data.secondNum <= 0) {
that.setData({
secondNum: 0
})
}
day = day > 9 ? day : '0' + day
hour = hour > 9 ? hour : '0' + hour
minute = minute > 9 ? minute : '0' + minute
second = second > 9 ? second : '0' + second
wx.setStorageSync('timeLength', time)
that.setData({
timeLength: wx.getStorageSync('timeLength'),
dayNum: day,
hourNum: hour,
minuteNum: minute,
secondNum: second
})
}, 1000)
}


刚进入页面时时间减少不正常（+2秒-1秒） 跑一段时间后又正常了