简单讲述ondragstart、drag、ondragend、ondragenter、ondragover、ondrop、ondragleave七个与拖拽相关的监听事件，并运用实现拖拽过程放置样式变化

<template>
  <div :class="$options.name">
    <div class="drag" draggable @dragstart="dragstart" @drag="drag" @dragend="dragend" >被拖拽物体</div>
    <div class="drop" @dragover="$event.preventDefault()" @dragenter="dragenter" @drop="drop" @dragleave="dragleave" >放入的位置1</div>
    <div class="drop" @dragover="$event.preventDefault()" @dragenter="dragenter" @drop="drop" @dragleave="dragleave" >放入的位置2</div>
  </div>
</template>
<script>
export default {
  name: "testDrag",
  methods: {
    // 被拖拽物体的监听事件----------------------------------------
    dragstart(e) {
      let 需要传输的内容 = {
        cssText: `background-color: #F56C6C;color: white;font-size: 24px;`,
        text: `物体被放进来了`,
      };
      e.dataTransfer.setData("自定义字段名", JSON.stringify(需要传输的内容));
    },
    drag(e) {
      e.currentTarget.setAttribute("drag", true);
    },
    dragend(e) {
      e.currentTarget.removeAttribute("drag");
    },
 
    // 放置区域的监听事件----------------------------------------
    dragenter(e) {
      e.currentTarget.setAttribute("dragenter", true);
    },
    drop(e) {
      e.currentTarget.removeAttribute("dragenter");
      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;
    },
    dragleave(e) {
      e.currentTarget.removeAttribute("dragenter");
    },
  },
};
</script>
<style lang="scss" scoped>
.testDrag {
  .drag {
    width: 100px;
    height: 100px;
    box-sizing: border-box;
    border: 1px solid #eee;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    &[drag] {
      color: #f56c6c;
      border-color: #f56c6c;
      &::after {
        content: "拖拽中";
        position: absolute;
        right: 0;
        top: 0;
        background-color: #f56c6c;
        color: white;
        font-size: 14px;
      }
    }
  }
  .drop {
    margin-top: 20px;
    width: 200px;
    height: 200px;
    box-sizing: border-box;
    border: 1px solid #eee;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    position: relative;
    &[dragenter] {
      color: #f56c6c;
      border-color: #f56c6c;
      &::after {
        content: "物体进入区域";
        position: absolute;
        right: 0;
        top: 0;
        background-color: #f56c6c;
        color: white;
        font-size: 14px;
      }
    }
  }
}
</style>