<template>
 <div class="wrap">
//months是一个包含十二个月名字的数组，用v-for对其进行循环渲染，并且把月份的index传给子组件
  <div v-for='(items, index) in months' v-if="index == monthIndex">
  <month :monthName='items' 
        :year='year' //年份传给子组件，年份在mounted里面计算得出
        :monthIndex='index' //月份传给子组件
        :day='today'//当日日期传给子组件
        :key='index' >
    </month>
  </div>
 </div>
</template>
 
//data部分
 data () {
   return {
   monthIndex: 0,
   months:['January', 'February', 'March', 'April', 
          'May', 'June', 'July', 'August', 
          'September', 'October', 'November', 'December'],
   year:-1,
   day:-1,
   }
  },

//父组件 
mounted () {
  let myDate = new Date();
  this.monthIndex = myDate.getMonth();
  this.year = myDate.getFullYear(); 
  this.today = myDate.getDate() - 1;
  },

//index值为0-41
<div v-for="(item, index) in days" :key='index' 
class="dayIndex" @click='choose(index)' 
:class="{choose: day == index}"> //动态绑定样式

if (new Date().getMonth() == this.monthIndex) {
 this.chooseIndex = this.day + this.firstDayIndex;
}

new Date(year + '/' + monthIndex + '/' + '01').getDay();

monthLastDay:{
 0:31,
 1:28,
 2:31,
 3:30,
 4:31,
 5:30,
 6:31,
 7:31,
 8:30,
 9:31,
 10:30,
 11:31
},

getMonthLastDay (year, month){
 if (month != 1) {
 return this.monthLastDay[month];
 } else {
    //this.leapyear是布尔值 它表示该年是否为闰年
 if (this.leapyear) {
  return 29;
 } else {
  return 28;
 }
 }
},

//index为上个月最后一天的日期 lastDayNum为上个月剩余天数
generateDays (index, lastDayNum) {
 let temp = 1;
 //这个for循环是push上个月的剩余日期，
 for (let i = lastDayNum; i > 0; i--) {
  this.days.push([(index - i + 1).toString()]);
 }
    //index置1，开始push本月天数
 index = 1;
 for (let i = 0; i < 42 - lastDayNum; i++) {
  //闰年二月
  if (this.leapyear) {
  if (index <= 29) {
   this.days.push(index.toString());
  }
  //非闰年月份
  } else if (index <= this.monthLastDay[this.monthIndex]) {
   this.days.push(index.toString());
   //这个else是push下个月的日期
  } else {
   this.days.push([temp.toString()]);
   temp++;
  }
  index++;
  }
 },

<div v-for="(item, index) in days" :key='index' 
class="dayIndex" @click='choose(index)' 
:class="{choose: chooseIndex == index}">
  //item为string 为本月日期
 <div v-if="typeof(item) == 'string'">
 {{item}}
 </div>
  //否则为非本月日期 添加class setGrey
 <div v-else class="setGrey">
 {{item[0]}}
 </div>
</div>