getTime()的兼容性（ios）

时间格式为：2017-12-12 12:00:00在苹果上获取时间戳有兼容性问题

需要转换成2017/12/12 12:00:00 才可以正确获取到时间戳

      let u = navigator.userAgent;   //判断浏览器型号
      let isAndroid = u.indexOf('Android') > -1 || u.indexOf('Adr') > -1;   //android终端
      let isiOS = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/); //ios终端
      if(isiOS){
        let time = new Date((v[0].createTime).replace(/-/g,'/')).getTime();
         this.timeago=this.getDateDiff(time);
      }else{
        let time = new Date(v[0].createTime).getTime();
         this.timeago=this.getDateDiff(time);
      }

判断时间过去了多久
    getDateDiff(dateTimeStamp){
    let result;
    let minute = 1000 * 60;
    let hour = minute * 60;
    let day = hour * 24;
    let halfamonth = day * 15;
    let month = day * 30;
    let now = new Date().getTime();
    let diffValue = now - dateTimeStamp;
    if(diffValue < 0){
      return;
    }
    let monthC =diffValue/month;
    let weekC =diffValue/(7*day);
    let dayC =diffValue/day;
    let hourC =diffValue/hour;
    let minC =diffValue/minute;
    if(monthC>=1){
      if(monthC<=12)
        result="" + parseInt(monthC) + "月前";
      else{
        result="" + parseInt(monthC/12) + "年前";
      }
    }
    else if(weekC>=1){
      result="" + parseInt(weekC) + "周前";
    }
    else if(dayC>=1){
      result=""+ parseInt(dayC) +"天前";
    }
    else if(hourC>=1){
      result=""+ parseInt(hourC) +"小时前";
    }
    else if(minC>=1){
      result=""+ parseInt(minC) +"分钟前";
    }else{
      result="刚刚";
    }
    return result;
  },