使用vant ui list列表check方法检查滚动跳的位置

可以使用`scroll-to-index`和`on-scroll`两个事件来实现。首先，在list组件上添加`ref`属性，然后在mounted生命周期中获取该组件的高度和每个item的高度。接着，监听`on-scroll`事件，获取当前滚动的距离并计算当前滚动到了第几个item，再触发`scroll-to-index`事件将该item滚动到可视区域内。代码示例：

<template>
  <van-list ref="list" :height="listHeight" :item-height="itemHeight" @scroll-to-index="scrollToIndex" @on-scroll="onScroll">
    <van-checkbox v-model="checkedList" :label="item" v-for="item in list" :key="item">{{ item }}</van-checkbox>
  </van-list>
</template>
<script>
export default {
  data() {
    return {
      list: ['选项1', '选项2', '选项3', '选项4', '选项5', '选项6', '选项7', '选项8', '选项9', '选项10'],
      checkedList: [],
      listHeight: 0,
      itemHeight: 0
    }
  },
  mounted() {
    this.listHeight = this.$refs.list.$el.clientHeight
    this.itemHeight = this.$refs.list.$el.querySelector('.van-checkbox').clientHeight
  },
  methods: {
    onScroll(event) {
      const scrollTop = event.target.scrollTop
      const index = Math.floor(scrollTop / this.itemHeight)
      this.$refs.list.scrollTo(index)
    },
    scrollToIndex(index) {
      this.$refs.list.scrollTo(index)
    }
  }
}
</script>