图文消息，标题不显示

<xml>
  <ToUserName>opS5nt1AyMiz0rgj_NWART1sdR7w</ToUserName>
  <FromUserName>gh_0e518917d4b2</FromUserName>
  <CreateTime>1466494026612</CreateTime>
  <MsgType>news</MsgType>
  <ArticleCount>1</ArticleCount>
  <Articles>
    <item>
      <title>Little dog</title>
      <Description>a clover dog</Description>
      <PicUrl>http://6f7d104c.ngrok.io/app/resources/images/dog.jpg</PicUrl>
      <Url>www.imooc.com</Url>
    </item>
  </Articles>
</xml>

xml中有设置为什么没有显示出来