// 拖拽文件夹
dropFolders (e) {
  e.stopPropagation()
  e.preventDefault()
  var items = e.dataTransfer.items
  for (var i = 0; i < items.length; i++) {
    var item = items[i].webkitGetAsEntry()
    if (item) {
      this.checkFolders(item)
    }
  }
}

// 判断是否为文件夹
checkFolders (item) {
  if (item.isDirectory) {
    this.traverseFileTree(item)
  } else {
    this.$alert('只支持上传文件夹', '提示', {
      confirmButtonText: '确定'
    })
  }
}

traverseFileTree (item, path, parentDir) {
  path = path || ''
  if (item.isFile) {
    item.file((file) => {
        let obj = {
          file: file,
          path: path + file.name,
          attr: item.attr
        }
        this.filesList.push(obj)
    })
  } else if (item.isDirectory) {
    var dirReader = item.createReader()
    dirReader.readEntries((entries) => {
      for (let i = 0; i < entries.length; i++) {
        entries[i].attr = item.attr
        this.traverseFileTree(entries[i], path + item.name + '/', temp)
      }
    }, function (e) {
      console.log(e)
    })
  }
}