<p ref="onloadCon" class="onloadCon" :class="{'drop-active': dropActive}">將文件拖拽到此處上傳</p>

data() {
  return {
     dropActive: false
  }
},
mounted() {
  const dropArea = this.$refs.onloadCon;
  dropArea.addEventListener("drop", this.dropEvent, false);
  dropArea.addEventListener("dragleave", (e) => {
    e.preventDefault();
    this.dropActive = false;
  }, false);
  dropArea.addEventListener("dragenter", (e) => {
    e.preventDefault();
    this.dropActive = true;
  }, false);
  dropArea.addEventListener("dragover", (e) => {
    e.preventDefault();
    this.dropActive = true;
  }, false);
},
methods: {
  dropEvent(e) {
     const files = e.dataTransfer.files;
     e.preventDefault();
     this.dropActive = false;
     // this.excelChange(files); 文件處理
  }
}