RubyOnRails 发送 mail 带附件

content_type "multipart/mixed"        #邮件里带内容和附件
    part "multipart/alternative" do |alternative|
      alternative.part "text/html" do |html|
        html.body = render_message("test.text.html", body)
      end
      alternative.part "text/plain" do |plain|
        plain.body = render_message("test.text.plain", body)
      end
    end
    @data = ""

    file_name = "/images/test.png"
    File.open(file_name,"rb").each {|read| @data << read}
    attachment :content_type => "image/png", :filename => File.basename(file_name), :body => @data

attachment :content_type => "image/png", :filename => File.basename(file_name), :body => @data

<img src="test.png" alt="test mail with picture"/>