getCurrentMonthLast: (date) => {
    var endDate = new Date(date); //date 是需要传递的时间如：2018-08
    var month = endDate.getMonth();
    var nextMonth = ++month;
    var nextMonthFirstDay = new Date(endDate.getFullYear(), nextMonth, 1);
    var oneDay = 1000 * 60 * 60 * 24;
    var dateString = new Date(nextMonthFirstDay - oneDay);
    return dateString.toLocaleDateString(); //toLocaleDateString() 返回 如：2018/8/31
  },