在Vue上模式关闭时,如何运行语句?

我的Vue组件如下:

<template>
    ...
    <b-modal ref="modal" id="modalInvoice" size="lg"  title="Invoice">
        <Invoice/>
        <div slot="modal-footer" class="w-100"> 
            <b-btn size="sm" class="float-right" variant="warning" @click="show=false">
                <i class="fa fa-print"></i> Print
            </b-btn>
        </div>
    </b-modal>

    ...
        <b-btn variant="warning" class="btn-square mt-2" v-b-modal.modalInvoice @click="checkout()"><i class="fa fa-credit-card-alt"></i>Checkout</b-btn>
    ...
</template>
<script>
    ...
    export default {
        ...
        mounted() {
            $(this.$refs.modal).on('hidden.bs.modal', () => {
                console.log('close modal')
            })
        },
    }
</script>

我试着这么做。所以我试着用 ref="modal" 并安装。但它不起作用。如果模式关闭,则不显示console.log

我怎样才能解决这个问题?