微信公众平台开发中如何使用.Net代码实现发送图文消息功能

protected string sendPicTextMessage(Msg _mode,string title,string description,string picurl,string url)
  {
    
    string res = string.Format(@"<xml>
    <ToUserName><![CDATA[{0}]]></ToUserName>
    <FromUserName><![CDATA[{1}]]></FromUserName>
    <CreateTime>{2}</CreateTime>
    <MsgType><![CDATA[news]]></MsgType>
    <ArticleCount>1</ArticleCount>
    <Articles>
     <item>
     <Title><![CDATA[{3}]]></Title> 
     <Description><![CDATA[{4}]]></Description>
     <PicUrl><![CDATA[{5}]]></PicUrl>
     <Url><![CDATA[{6}]]></Url>
     </item>
     </Articles>
     </xml> ",
      _mode.FromUserName, _mode.ToUserName, DateTime.Now,title, description, picurl, url);

    return res;

   }

protected void Page_Load(object sender, EventArgs e)
   {
    
     MyMenu();
     wxmessage wx = GetWxMessage();
     string res = "";

     if (!string.IsNullOrEmpty(wx.EventName) && wx.EventName.Trim() == "subscribe")
     {
       string content = "";
       content = "/:rose欢迎北京永杰友信科技有限公司/:rose\n直接回复“你好”";
       res = sendTextMessage(wx, content);
     }
     else if (!string.IsNullOrEmpty(wx.EventName) && wx.EventName.Trim() == "CLICK")
     {
       if(wx.EventKey=="Hello")
         res = sendTextMessage(wx, "你好,欢迎使用北京永杰友信科技有限公司公共微信平台!");
       if(wx.EventKey=="P1")
         res = sendTextMessage(wx, "你好,点击了产品1");
       if(wx.EventKey=="P2")
         res = sendTextMessage(wx, "你好,点击了产品2");
     }
     else
     {
       if (wx.MsgType == "text" && wx.Content == "你好")
       {
         res = sendTextMessage(wx, "你好,欢迎使用北京永杰友信科技有限公司公共微信平台!");
       }
       if (wx.MsgType == "text" && wx.Content == "图文")
       {
         res = sendPicTextMessage(wx,"这里是一个标题","这里是摘要","https://cache.yisu.com/upload/information/20201208/265/31137.png","http://www.4ugood.net");
       }
       else if (wx.MsgType == "voice")
       {
         res = sendTextMessage(wx, wx.Recognition);
       }
       else
       {
         res = sendTextMessage(wx, "你好,未能识别消息!");
       }
     }

     Response.Write(res);
   }



   private wxmessage GetWxMessage()
   {
     wxmessage wx = new wxmessage();
     StreamReader str = new StreamReader(Request.InputStream, System.Text.Encoding.UTF8);
     XmlDocument xml = new XmlDocument();
     xml.Load(str);
     wx.ToUserName = xml.SelectSingleNode("xml").SelectSingleNode("ToUserName").InnerText;
     wx.FromUserName = xml.SelectSingleNode("xml").SelectSingleNode("FromUserName").InnerText;
     wx.MsgType = xml.SelectSingleNode("xml").SelectSingleNode("MsgType").InnerText;
     if (wx.MsgType.Trim() == "text")
     {
       wx.Content = xml.SelectSingleNode("xml").SelectSingleNode("Content").InnerText;
     }
     if (wx.MsgType.Trim() == "event")
     {
       wx.EventName = xml.SelectSingleNode("xml").SelectSingleNode("Event").InnerText;
       wx.EventKey = xml.SelectSingleNode("xml").SelectSingleNode("EventKey").InnerText;
     }
     if (wx.MsgType.Trim() == "voice")
     {
       wx.Recognition = xml.SelectSingleNode("xml").SelectSingleNode("Recognition").InnerText;
     }
     
     return wx;
   }