需求：选择日期后，点击确定按钮关闭面板

思路：

1. 使用shortcuts自定义确定和取消按钮
2. 选择日期后使用handleOpen()强制开启面板
3. 点击确定后使用handleClose()关闭面板

<template>
    <el-date-picker
        ref="pickerRef"
        v-model="dateValue"
        type="daterange"
        range-separator="To"
        start-placeholder="Start date"
        end-placeholder="End date"
        :shortcuts="shortcuts"
        @change="dateChange"
        @focus="focusChange"
    />
</template>

<script setup>
    import { ref, nextTick } from 'vue'
    import { ElButton, ElDatePicker } from 'element-plus'

    const dateValue = ref('')
    const pickerRef = ref(null)
    let isClickPicker = false
    const shortcuts = ref([
        {
            text: '取消',
            onClick(picker) {
                console.log('点击取消')
                isClickPicker = true
                pickerRef.value && pickerRef.value.handleClose()
                setTimeout(() => {
                    dateValue.value = ''
                }, 10)
            }
        },
        {
            text: '确定',
            onClick(picker) {
                // 关闭面板
                isClickPicker = true
                console.log('点击确定')
                if(!dateValue.value) {
                  // message.warning('请选择日期！')
                  console.log('请选择日期！')
                  return false
                }
                pickerRef.value && pickerRef.value.handleClose()
            }
        }
    ])
    const dateChange = (date) => {
        pickerRef.value && pickerRef.value.handleOpen()
    }
    const focusChange = () => {
        // 点击确定后聚焦，强制关闭面板
        if (isClickPicker) {
            pickerRef.value && pickerRef.value.handleClose()
            isClickPicker = false
        }
    }
</script>

<style>
    .el-picker-panel__body-wrapper {
        height: 108%;
        border: 1px solid #e4e4e4;
        width: 100%;
    }
    .el-date-picker.has-sidebar {
        width: 330px !important;
    }
    .el-picker-panel__sidebar {
        right: 0px;
        top: 310px !important;
        width: 150px;
        display: flex;
    }
    .el-picker-panel__body {
        padding-bottom: 20px;
        margin-left: 0px !important;
    }
</style>