CSV文件下载，用excel打开会出现的乱码问题的解决办法

CSV下载时，如果使用官方文档的说明，下载后的文件用excel打开时，　会产生乱码．

问题的根源有两点：

１．　文件需要指定好　encoding,

２．　windows 与　mac下的　csv的分隔符是不一样的．　我服了．．．

  require 'csv'
  def download_csv
    filename = "机型名单"
    options = client_is_mac? ? { :col_sep => ";" } : {}
    file = CSV.generate(options) do |csv|
      csv << ["品牌", "机型名称", "UA里的机型名称", "价格"]
      CellPhone.all.each do |cell_phone|
        csv << [cell_phone.brand, cell_phone.name, cell_phone.ua_name, cell_phone.price]
      end
    end
    send_data file.encode("gbk", "utf-8"), :type => 'text/csv; charset=gbk; header=present', :disposition => "attachment;filename=#{filename}.csv"
  end