uiapp使用vue3的语法实现月份选择器

好的，以下是一个使用 Vue3 的语法实现月份选择器的示例代码：

<template>
  <div class="month-picker">
    <input type="text" v-model="selectedMonth" readonly @click="showPicker" />
    <div class="picker" v-show="isPickerVisible">
      <div class="header">
        <button @click="previousYear">&lt;&lt;</button>
        <button @click="previousMonth">&lt;</button>
        <span>{{ currentYear }} 年 {{ currentMonth }} 月</span>
        <button @click="nextMonth">&gt;</button>
        <button @click="nextYear">&gt;&gt;</button>
      </div>
      <div class="body">
        <div class="month" v-for="(month, index) in months" :key="index" @click="selectMonth(month)">
          {{ month }}
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import { ref, computed } from 'vue';

export default {
  name: 'MonthPicker',
  setup() {
    const selectedMonth = ref('');
    const isPickerVisible = ref(false);
    const currentYear = ref(new Date().getFullYear());
    const currentMonth = ref(new Date().getMonth() + 1);

    const months = computed(() => {
      const result = [];
      for (let i = 1; i <= 12; i++) {
        result.push(`${i} 月`);
      }
      return result;
    });

    const showPicker = () => {
      isPickerVisible.value = true;
    };

    const hidePicker = () => {
      isPickerVisible.value = false;
    };

    const previousMonth = () => {
      if (currentMonth.value === 1) {
        currentMonth.value = 12;
        currentYear.value -= 1;
      } else {
        currentMonth.value -= 1;
      }
    };

    const nextMonth = () => {
      if (currentMonth.value === 12) {
        currentMonth.value = 1;
        currentYear.value += 1;
      } else {
        currentMonth.value += 1;
      }
    };

    const previousYear = () => {
      currentYear.value -= 1;
    };

    const nextYear = () => {
      currentYear.value += 1;
    };

    const selectMonth = (month) => {
      selectedMonth.value = month;
      hidePicker();
    };

    return {
      selectedMonth,
      isPickerVisible,
      currentYear,
      currentMonth,
      months,
      showPicker,
      hidePicker,
      previousMonth,
      nextMonth,
      previousYear,
      nextYear,
      selectMonth,
    };
  },
};
</script>

<style scoped>
.month-picker {
  position: relative;
}

.picker {
  position: absolute;
  top: 100%;
  left: 0;
  z-index: 1;
  background-color: #fff;
  border: 1px solid #ccc;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px;
  background-color: #f5f5f5;
}

.header button {
  border: none;
  background-color: transparent;
  font-size: 14px;
  cursor: pointer;
}

.body {
  display: flex;
  flex-wrap: wrap;
  padding: 8px;
}

.month {
  flex-basis: 25%;
  padding: 8px;
  text-align: center;
  cursor: pointer;
}

.month:hover {
  background-color: #f5f5f5;
}
</style>

这个月份选择器组件包含一个输入框和一个下拉框，用户可以通过点击输入框来显示下拉框，从而选择一个月份。下拉框显示了当前年份和月份，以及所有的月份选项。用户可以通过点击月份选项来选择一个月份，选择后下拉框会自动隐藏并将选择的月份显示在输入框中。用户还可以通过左右箭头按钮来切换年份和月份。