Vue2实现组件延迟加载的示例代码

export default function defer(maxFrameCount) {
  return {
    data() {
      return {
        frameCount: 0,
      };
    },
    mounted() {
      const refreshFrame = () => {
        requestAnimationFrame(() => {
          this.frameCount++;
          if (this.frameCount < maxFrameCount) {
            refreshFrame();
          }
        });
      };
      refreshFrame();
    },
    methods: {
      deferItem(showFrameCount) {
        return this.frameCount >= showFrameCount;
      },
    },
  };
}

<template>
  <div class="container">
    <div v-for="n in 20000" class="item"></div>
  </div>
</template>

<script></script>
<style scoped>
.container {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  width: 300px;
  height: 300px;
}

.item {
  width: 5px;
  height: 5px;
  background-color: #eee;
  margin: 0.1em;
}
</style>

<template>
  <div class="container">
    <div v-for="n in 25" :key="n" class="wrapper">
      <HeavyComp v-if="deferItem(n)" />
    </div>
  </div>
</template>

<script>
import HeavyComp from "./components/HeavyComp.vue";
import defer from "./mixins/defer";
export default {
  components: {
    HeavyComp,
  },
  mixins: [defer(25)],
};
</script>
<style scoped>
.container {
  display: flex;
  flex-wrap: wrap;
}
.wrapper {
  border: 1px solid salmon;
}
</style>