js回到顶部

    <v-fab-transition>
      <v-btn v-if="!hidden" color="primary" dark fixed bottom right fab @click="scrollTop">
        <v-icon>mdi-chevron-up</v-icon>
      </v-btn>
    </v-fab-transition>

hidden: true,
    window.addEventListener('scroll', () => {
      let scrollTop = document.documentElement.scrollTop
      if (scrollTop > 100) {
        this.hidden = false
      } else {
        this.hidden = true
      }
    })
    scrollTop () {
      window.scrollTo({
        top: 0,
        behavior: 'smooth'
      })
    },