Android系统可以获取到page.data中的howDays更改后的数据，iOS系统显示是null，问题是new Date()方法在苹果ios端返回数据为空 new Date(12 + ‘-’ + 12 + ‘-’ + 2000);

部分源码如下：

data: {

dayAndMonth: {

howDays: ‘’,

},

}

btnCount_Click: function (s1, s2) { //s1=2018-08-21  s2=2018-08-23

var that = this;

var days = that.DateDiff(s1, s2);

that.setData({

dayAndMonth: {

howDays: days

}

});

},

DateDiff: function (sDate1, sDate2) { //sDate1和sDate2是2000-12-12格式  

var aDate, oDate1, oDate2, iDays

aDate = sDate1.split("-")

oDate1 = new Date(aDate[1] + ‘-’ + aDate[2] + ‘-’ + aDate[0]) //转换为12-12-2000格式  

aDate = sDate2.split("-")

oDate2 = new Date(aDate[1] + ‘-’ + aDate[2] + ‘-’ + aDate[0])

iDays = parseInt(Math.abs(oDate1 - oDate2) / 1000 / 60 / 60 / 24) //把相差的毫秒数转换为天数  

return iDays;

},