def to_xlsx(file_path=nil, file_name=nil)
      file_path ||= self.class.xlsx_file_path
      file_name ||= self.class.xlsx_file_name
      path = to_xlsx_file(file_path, file_name)
      # TODO: 讀取檔案回傳
      File.open(path, 'rb') { |f| f.read }
    end
def to_xlsx(file_path=nil, file_name=nil)
      file_path ||= self.class.xlsx_file_path
      file_name ||= self.class.xlsx_file_name
      path = to_xlsx_file(file_path, file_name)
      # TODO: 讀取檔案回傳
      File.open(path, 'rb') { |f| f.read }
    end
新版 Excel