效果图

组件代码

<template>
  <div class="calendar">
    <slot name="header">
      <div class="top">
        <div class="current">{{ time }}</div>
        <div class="box">
          <div class="btn" @click="btn('prevMonth')">上个月</div>
          <div class="btn" @click="btn('currentMonth')">当前月</div>
          <div class="btn" @click="btn('nextMonth')">下个月</div>
        </div>
      </div>
    </slot>
    <div class="date">
      <div class="item">日</div>
      <div class="item">一</div>
      <div class="item">二</div>
      <div class="item">三</div>
      <div class="item">四</div>
      <div class="item">五</div>
      <div class="item">六</div>
      <template v-for="(item,index) in list">
        <div class="item" :class="{active:item.type === currentSelectDate,current:currentDate == item.type,grey:item.next||item.prve}" :key="item.type" @click="click(item)">
          <slot :index="index" :item="item">{{ item.date }}</slot>
        </div>
      </template>
    </div>
  </div>
</template>
<script>
export default {
  name: "Calendar",
  props: {
    value: { type: Date, default: () => new Date() }
  },
  data() {
    return {
      list: [],
      time: "",
      currentSelectDate: "",
      currentDate: ""
    };
  },
  watch: {
    value(a) {
      if (a) this.time = a;
      this.btn(0);
    }
  },
  created() {
    this.btn();
  },
  methods: {
    click(item) {
      if (this.currentSelectDate === item.type) {
        // 取消选中
        this.currentSelectDate = "";
        // 选中日期
      } else this.currentSelectDate = item.type;
      // 选中日期是上个月
      if (item.next) this.btn("nextMonth");
      // 选中日期是下个月
      if (item.prve) this.btn("prevMonth");
      this.$emit("click", { ...item, selectDate: this.currentSelectDate });
      this.$emit("update:select-date", this.currentSelectDate);
    },
    // 默认当前月
    btn(type = "currentMonth") {
      // 获取指定时间的年份和月份
      let currentYear = new Date(this.time).getFullYear();
      let currentMonth = new Date(this.time).getMonth() + 1;
      // 点击上个月
      if (type === "prevMonth") {
        // 指定时间的月份为1月，上一月为上一年的12月
        if (currentMonth === 1) (currentMonth = 13), (currentYear = currentYear - 1);
        currentMonth--;
      }
      // 当前月
      if (type === "currentMonth") {
        // 获取当前时间的年月日
        currentYear = new Date().getFullYear();
        currentMonth = new Date().getMonth() + 1;
        let currentDate = new Date().getDate();
        this.currentDate = `${currentYear}-${currentMonth > 9 ? currentMonth : "0" + currentMonth}-${currentDate > 9 ? currentDate : "0" + currentDate}`;
      }
      // 下个月
      if (type === "nextMonth") {
        // 指定时间的月份为12月，下一月为下一年的1月
        if (currentMonth === 12) (currentMonth = 0), (currentYear = currentYear + 1);
        currentMonth++;
      }
      // 当前日历展示的年月
      this.time = `${currentYear}-${currentMonth > 9 ? currentMonth : "0" + currentMonth}`;
      let date = `${currentYear}-${currentMonth > 9 ? currentMonth : "0" + currentMonth}-01`;
      this.init(date);
      this.$emit("change-month", { currentYear, currentMonth, type, date });
      this.$emit("update:current-date", this.currentDate);
    },
    // 生成日历日期，因每月开始和结束不是周日和周六，需要取上月月末和下月月初补满每周七天，所以生成的总天数共35-42天。
    init(time) {
      // 获得指定时间年月，月总天数
      let date = new Date(time);
      let currentYear = date.getFullYear(); // 年
      let currentMonth = date.getMonth() + 1; // 月
      let currentMonthDate = new Date(currentYear, currentMonth, 0).getDate(); // 当月总天数
      let list = new Array(currentMonthDate).fill().map((_, i) => ({ year: currentYear, month: currentMonth, date: i + 1 }));

      // 获取上月，需要处理跨年
      let preMonth = currentMonth;
      if (preMonth === 1) (preMonth = 13), (currentYear = currentYear - 1);
      let beforeMonthDate = new Date(currentYear, preMonth - 1, 0).getDate(); // 上月总天数
      let beforeDate = new Date(`${currentYear}-${preMonth - 1}-${beforeMonthDate}`).getDay();
      for (let i = 0; i <= beforeDate; i++) list.unshift({ prve: true, year: currentYear, month: preMonth - 1, date: beforeMonthDate - i });

      // 获取下月，需要处理跨年
      let nextMonth = currentMonth;
      if (nextMonth === 12) (nextMonth = 0), (currentYear = currentYear + 1);
      let afterDate = 7 - ((currentMonthDate + beforeDate) % 7); // 下月月头
      for (let i = 1; i < afterDate; i++) list.push({ next: true, year: currentYear, month: nextMonth + 1, date: i });
      this.list = list.map((e, i) => {
        let { year, month, date } = e;
        return { ...e, week: Math.floor(i % 7), type: `${year}-${month > 9 ? month : "0" + month}-${date > 9 ? date : "0" + date}` };
      });
    }
  }
};
</script>
<style lang='less' scoped>
.calendar {
  min-height: 300px;
  .top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 40px;
    margin: 0 0 20px 0;
    padding: 0 10px;
  }
  .box {
    display: flex;
    justify-content: space-evenly;
    width: 160px;
    border: 1px solid #eee;
    border-radius: 5px;
    margin: 5px;
    color: #666;
    .btn {
      padding: 3px 5px;
      cursor: pointer;
      transition: all 0.1s;
      &:nth-child(2) {
        border: 1px solid #eee;
        border-top: none;
        border-bottom: none;
      }
      &:hover {
        color: #333;
        background: #eee;
        transition: all 0.1s;
      }
    }
  }
  .item {
    flex: 0 0 13%;
    height: 35px;
    margin: 2px;
    min-width: 20px;
    text-align: center;
    color: #444;
    padding-top: 5px;
    box-sizing: border-box;
    border-radius: 5px;
    transition: all 0.2s;
    &.grey {
      color: #999;
    }
    &:hover {
      transition: all 0.2s;
      cursor: pointer;
      background: #5164e7a0;
      color: #fff;
    }
    &.current {
      transition: all 0.2s;
      background: #5164e7a0;
      color: #fff;
    }
    &.active {
      transition: all 0.2s;
      background: #5164e7;
      color: #fff;
    }
  }
  .date {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
  }
}
</style>

<template>
  <div class="calendar">
    <div class="head">
      <div class="top">
        <el-date-picker class="pick" ref="time" v-model="Time" type="date" placeholder="选择日期" :editable="false"
          :clearable="false" size="small" format="YYYY-MM-DD" value-format="YYYY-MM-DD" @change="handlerDate" />
        <div class="box">
          <div class="btn" @click="handlerDate('prevMonth')">上个月</div>
          <div class="btn" @click="handlerDate('currentMonth')">当前月</div>
          <div class="btn" @click="handlerDate('nextMonth')">下个月</div>
        </div>
      </div>
      <div class="bottom">
        <slot name="tips"> </slot>
      </div>
    </div>
    <div class="date">
      <div class="item">日</div>
      <div class="item">一</div>
      <div class="item">二</div>
      <div class="item">三</div>
      <div class="item">四</div>
      <div class="item">五</div>
      <div class="item">六</div>
      <template v-for="(item, index) in List" :key="item.time">
        <div class="item"
          :class="{ active: item.time === Time, current: currentDate == item.time, grey: item.next || item.prve }"
          @click="click(item)">
          <slot :index="index" :item="item">{{ item.date }}</slot>
        </div>
      </template>
    </div>
  </div>
</template>
<script setup lang="ts" name="Calendar">
import { watch, toRefs, computed, reactive } from 'vue';
const emit = defineEmits(['changeDate', 'update:currentDate', 'change-month'])
const props = defineProps({
  currentDate: {
    type: String,
    default: ''
  }
});
const Data = reactive<{
  selectMonth: string,
  List: Array<Object>,
}>({
  selectMonth: '',
  List: []
})
const { currentDate } = toRefs(props);
const { selectMonth, List } = toRefs(Data)

const Time = computed({
  set: (val) => emit("update:currentDate", val),
  get: () => currentDate.value
})
// 点击日历
function click(item: Object) {
  let { year, month, date, week, time } = item;
  if (time) Time.value = time;
  if (month != selectMonth.value) {
    emit("change-month", month)
    handlerDate();
  }
  emit("changeDate");
}
// 处理日期时间
function handlerDate(type?: any) {
  let date = Time.value ? new Date(Time.value) : new Date();
  if (type == 'currentMonth') date = new Date();
  // 获取指定时间的年份和月份
  let currentYear: string | number = date.getFullYear();
  let currentMonth: string | number = date.getMonth() + 1;
  let currentDate: string | number = date.getDate();
  // 点击上个月
  if (type === "prevMonth") {
    // 指定时间的月份为1月，上一月为上一年的12月
    if (currentMonth === 1) {
      currentMonth = 12;
      currentYear = currentYear - 1;
    } else {
      currentMonth--;
    }
  }
  // 下个月
  if (type === "nextMonth") {
    // 指定时间的月份为12月，下一月为下一年的1月
    if (currentMonth === 12) {
      currentMonth = 1;
      currentYear = currentYear + 1;
    } else {
      currentMonth++;
    }
  }

  currentMonth = currentMonth.toString().padStart(2, '0');
  currentDate = currentDate.toString().padStart(2, '0');
  // 当前日历展示的年月日    
  Time.value = `${currentYear}-${currentMonth}-${currentDate}`;
  selectMonth.value = currentMonth;
  init(currentYear, +currentMonth);
}
// 生成日历日期，因每月开始和结束不是周日和周六，需要取上月月末和下月月初补满每周七天，所以生成的总天数共35-42天。
function init(year: number, month: number) {
  // 获得指定时间年月，月总天数
  let date = new Date(year, month - 1);
  let currentYear = date.getFullYear(); // 年
  let currentMonth = date.getMonth() + 1; // 月
  let currentMonthDate = new Date(currentYear, currentMonth, 0).getDate(); // 当月总天数
  let list: Array<Object> = new Array(currentMonthDate).fill(1).map((_, i) => ({ year: currentYear, month: currentMonth, date: i + 1 }));

  // 获取上月，需要处理跨年
  let preMonth = currentMonth;
  let preYear = currentYear;
  if (preMonth === 1) (preMonth = 13), (preYear = preYear - 1);
  let beforeMonthDate = new Date(currentYear, preMonth - 1, 0).getDate(); // 上月总天数
  let beforeDate = new Date(`${currentYear}-${preMonth - 1}-${beforeMonthDate}`).getDay(); //获取上月最后一天是周几
  for (let i = 0; i <= beforeDate; i++) list.unshift({ prve: true, year: preYear, month: preMonth - 1, date: beforeMonthDate - i });

  // 获取下月，需要处理跨年
  let nextMonth = currentMonth;
  let nextYear = currentYear;
  if (nextMonth === 12) (nextMonth = 0), (nextYear = nextYear + 1);
  // let afterDate = 7 - ((currentMonthDate + beforeDate) % 7); // 下月月头，按周填充补满
  let afterDate = 42 - (currentMonthDate + beforeDate); // 下月月头，按照每月5周填充
  for (let i = 1; i < afterDate; i++) list.push({ next: true, year: nextYear, month: nextMonth + 1, date: i });

  List.value = list.map((e, i) => {
    let { year, month, date } = e;
    return { year, month, date, week: Math.floor(i % 7), time: `${year}-${month.toString().padStart(2, 0)}-${date.toString().padStart(2, 0)}` };
  });

}
handlerDate()
</script>
<style lang='scss' scoped>
.calendar {
  min-height: 360px;
  overflow: hidden;

  .head {
    margin: 0 0 15px 0;
    padding: 0 10px;

    .top {
      display: flex;
      justify-content: space-between;
      align-items: center;

      & :deep(.pick.el-input) {
        width: 80px;

        .el-input__prefix,
        .el-input__suffix {
          display: none;
        }

        .el-input__wrapper {
          box-shadow: none;
          text-align: left;
          padding-left: 0;
          padding-right: 0;
        }
      }
    }

    .bottom {
      height: 35px;
      line-height: 35px;
    }
  }

  .box {
    display: flex;
    justify-content: space-evenly;
    width: 160px;
    border: 1px solid #eee;
    border-radius: 5px;
    margin: 5px;
    color: #666;

    .btn {
      padding: 3px 5px;
      cursor: pointer;
      transition: all 0.1s;

      &:nth-child(2) {
        border: 1px solid #eee;
        border-top: none;
        border-bottom: none;
      }

      &:hover {
        color: #333;
        background: #eee;
        transition: all 0.1s;
      }
    }
  }

  .item {
    flex: 0 0 13%;
    height: 35px;
    margin: 2px;
    min-width: 20px;
    text-align: center;
    color: #444;
    padding-top: 5px;
    box-sizing: border-box;
    border-radius: 5px;
    transition: all 0.2s;

    &.grey {
      color: #999;
    }

    &:hover {
      transition: all 0.2s;
      cursor: pointer;
      background: #5164e7a0;
      color: #fff;
    }

    &.current {
      transition: all 0.2s;
      background: #5164e7a0;
      color: #fff;
    }

    &.active {
      transition: all 0.2s;
      background: #5164e7;
      color: #fff;
    }
  }

  .date {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
  }
}
</style>