一个简单的Vue2例子讲明白拖拽drag、移入dragover、放下drop的触发机制先后顺序

<template>
  <div :class="$options.name">
    <div class="drag" draggable @dragstart="dragstart">被拖拽物体</div>
    <div class="drop" @dragover="$event.preventDefault()" @drop="drop">放入的位置</div>
  </div>
</template>
<script>
export default {
  name: "testDrag",
  methods: {
    dragstart(e) {
      let 需要传输的内容 = {
        cssText: `background-color: #F56C6C;color: white;font-size: 24px;`,
        text: `<p>支持HTML</p><br><b>显示这句话</b>`,
      };
      e.dataTransfer.setData("自定义字段名", JSON.stringify(需要传输的内容));
    },
    drop(e) {
      let 需要传输的内容 = JSON.parse(e.dataTransfer.getData("自定义字段名"));
      e.currentTarget.style.cssText = 需要传输的内容.cssText;
      e.currentTarget.innerHTML = 需要传输的内容.text;
    },
  },
};
</script>
<style lang="scss" scoped>
.testDrag {
  .drag {
    width: 100px;
    height: 100px;
    color: white;
    background-color: #f56c6c;
    display: flex;
    justify-content: center;
    align-items: center;
  }
  .drop {
    margin-top: 20px;
    width: 300px;
    height: 300px;
    background-color: #409eff;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
  }
}
</style>