<template>
  <div class="c-fixed-bottom">
    <!-- 空白占位 -->
    <div class="c-fixed-bottom__seat" />
    <div class="c-fixed-bottom__positioner" :style="customStyle">
      <slot></slot>
    </div>
  </div>
</template>

<script lang="ts">
import Vue from 'vue'
export default Vue.extend({
  props: {
    customStyle: {
      type: Object,
      default: () => ({}),
    },
  },
})
</script>

<style lang="less" scoped>
.c-fixed-bottom {
  &__positioner {
    background: #fff;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    box-shadow: 0 -2px 4px 0 rgba(0, 0, 0, 0.08);
    z-index: 99;
    border-style: solid;
    border-color: #fff;
  }

  @supports (height: constant(safe-area-inset-top)) {
    &__seat {
      height: constant(safe-area-inset-bottom); // 兼容 IOS < 11.2
    }

    &__positioner {
      border-bottom-width: constant(safe-area-inset-bottom); // 兼容 IOS < 11.2
    }
  }

  @supports (border-bottom-width: env(safe-area-inset-top)) {
    &__seat {
      height: env(safe-area-inset-bottom); // 兼容 IOS > 11.2;
    }

    &__positioner {
      border-bottom-width: env(safe-area-inset-bottom); // 兼容 IOS > 11.2;
    }
  }
}
</style>

在使用时候直接进行：

import FixedBottom from '@/components/fixed-bottom/index.vue'

components: {
    FixedBottom,
  },

<fixed-bottom> 这里面正常写底部样式就可以 </fixed-bottom>