/// <summary>
    /// 图文消息
    /// </summary>
    public class ResponseNews : ResponseBase
    {

        /// <summary>
        /// 图文条数，默认第一条为大图。图文数不能超过10，否则将会无响应
        /// </summary>
        public int ArticleCount
        {
            get
            {
                return ArticleCollection.Count;
            }
        }
        public string Articles { get; set; }

        /// <summary>
        /// 图文内容，集合
        /// </summary>
        public List<ArticleItem> ArticleCollection { get; set; }

        /// <summary>
        /// 构造函数,自动生成消息创建时间（整型）,参考：APITools.GetCreateTime()
        /// </summary>
        /// <param name="toUser">员工UserID </param>
        /// <param name="fromUser">企业号CorpID </param>
        /// <param name="content">文本消息内容  </param>
        public ResponseNews(string toUser, string fromUser)
            : base(RequestMessageType.news)
        {
            this.ToUserName = toUser;
            this.FromUserName = fromUser;
            this.CreateTime = CorpTools.GetCreateTime();

        }

        /// <summary>
        /// 获得XML文本
        /// </summary>
        /// <returns></returns>
        public override string GenerateXML()
        {
            /*
            const string xmlformat = @" <xml>
               <ToUserName><![CDATA[toUser]]></ToUserName>
               <FromUserName><![CDATA[fromUser]]></FromUserName>
               <CreateTime>12345678</CreateTime>
               <MsgType><![CDATA[news]]></MsgType>
               <ArticleCount>2</ArticleCount>
               <Articles>
                   <item>
                       <Title><![CDATA[title1]]></Title> 
                       <Description><![CDATA[description1]]></Description>
                       <PicUrl><![CDATA[picurl]]></PicUrl>
                       <Url><![CDATA[url]]></Url>
                   </item>
                   <item>
                       <Title><![CDATA[title]]></Title>
                       <Description><![CDATA[description]]></Description>
                       <PicUrl><![CDATA[picurl]]></PicUrl>
                       <Url><![CDATA[url]]></Url>
                   </item>
               </Articles>
            </xml>";
            */
            //获得文章列表xml
            string xmlArticles = "";
            foreach (ArticleItem item in ArticleCollection)
            {
                xmlArticles += item.GenerateXML();
            }

            string XML = " <xml>"
                            + String.Format("<ToUserName><![CDATA[{0}]]></ToUserName>", ToUserName)
                            + String.Format("<FromUserName><![CDATA[{0}]]></FromUserName>", FromUserName)
                            + String.Format("<CreateTime>{0}</CreateTime>", CreateTime)
                            + String.Format("<MsgType><![CDATA[{0}]]></MsgType>", MsgType)
                            + String.Format("<ArticleCount>{0}</ArticleCount>", ArticleCollection.Count)
                            + String.Format("<Articles>{0}</Articles>", xmlArticles)
                        + "</xml>";
            return String.Format(xmlformat, ToUserName, FromUserName, CreateTime, MsgType, "");
        }
    }

    /// <summary>
    /// 图文消息，单图文类
    /// </summary>
    public class ArticleItem
    {
        /// <summary>
        /// 文章标题
        /// </summary>
        public string Title { get; set; }
        /// <summary>
        /// 文章描述
        /// </summary>
        public string Description { get; set; }
        /// <summary>
        /// 图片链接，支持JPG、PNG格式，较好的效果为大图360*200，小图200*200
        /// </summary>
        public string PicUrl { get; set; }
        /// <summary>
        /// 点击图文消息跳转链接
        /// </summary>
        public string Url { get; set; }

        public string GenerateXML()
        {
            string xml = "<item>"
                            + String.Format("<Title><![CDATA[{0}]]></Title>", Title)
                            + String.Format("<Description><![CDATA[{0}]]></Description>", Description)
                            + String.Format("<PicUrl><![CDATA[{0}]]></PicUrl>", PicUrl)
                            + String.Format("<Url><![CDATA[{0}]]></Url>", Url)
                        + "</item>";
            return xml;
        }
        public string GenerateJSON()
        {
            throw new NotImplementedException();
        }
    }