[UWP]涨姿势UWP源码——RSS feed的获取和解析

        public async Task<string> DownloadRssString()
        {
            var httpClient = new HttpClient();
            var result = await httpClient.GetStringAsync(new Uri("http://www.zhangzishi.cc/feed"));
            return result;
        }

<rss version="2.0"
    xmlns:content="http://purl.org/rss/1.0/modules/content/"
    xmlns:wfw="http://wellformedweb.org/CommentAPI/"
    xmlns:dc="http://purl.org/dc/elements/1.1/"
    xmlns:atom="http://www.w3.org/2005/Atom"
    xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
    xmlns:slash="http://purl.org/rss/1.0/modules/slash/">
  <channel>
    <title>涨姿势</title>
    <atom:link href="http://www.zhangzishi.cc/feed" rel="self" type="application/rss+xml" />
    <link>http://www.zhangzishi.cc</link>
    <description>骚年,来这里涨点姿势吧！</description>
    <lastBuildDate>Sun, 17 Jul 2016 04:37:46 +0800</lastBuildDate>
</channel>
</rss>

    <item>
      <title>日本某高校一男生在女生生日派对上公开表白，青春真好</title>
      <link>http://www.zhangzishi.cc/20160717zh.html</link>
      <comments>http://www.zhangzishi.cc/20160717zh.html#comments</comments>
      <pubDate>Sun, 17 Jul 2016 04:37:46 +0800</pubDate>
      <dc:creator><![CDATA[丁丁]]></dc:creator>
      <category><![CDATA[世界观]]></category>
      <guid isPermaLink="false">http://www.zhangzishi.cc/?p=178981</guid>
      <description><![CDATA[日本某高校一男生在女生生日派对上公开表白。“在这个世界上我最喜欢的人是你，我会好好珍惜你的。”看得本公举全程一 [&#8230;]]]></description>
      <content:encoded>
        <![CDATA[<p style="color: #444444;">日本某高校一男生在女生生日派对上公开表白。“在这个世界上我最喜欢的人是你，我会好好珍惜你的。”看得本公举全程一直傻笑，青春真好啊~</p>
<p><embed width="480" height="480" type="application/x-shockwave-flash" src="http://video.weibo.com/player/1034:7e3df996c2f5e9a1973974f0bb9e5e39/v.swf" allowscriptaccess="always" allowfullscreen="allowfullscreen" wmode="transparent" quality="high"></embed></p>
<p>视频链接：<a style="color: #428bca;" href="http://weibo.com/p/2304447e3df996c2f5e9a1973974f0bb9e5e39" target="_blank">http://weibo.com/p/2304447e3df996c2f5e9a1973974f0bb9e5e39</a><img src="http://cdnjp.zhangzishi.cc/wp-content/uploads/2016/05/024045ftw.jpg"  class="alignnone size-medium wp-image-171793" /></p>
<p>微信订阅号 zhangzishi_weixin 合作请直接联系 tintin@zhangzishi.cc</p>
]]>
      </content:encoded>
      <wfw:commentRss>http://www.zhangzishi.cc/20160717zh.html/feed</wfw:commentRss>
      <slash:comments>12</slash:comments>
    </item>

    public class Item
    {
        public string Title { get; set; }
        public Uri Link { get; set; }
        public DateTime PublishedDate { get; set; }
        public string Creator { get; set; }
        public string Category { get; set; }
        public string Description { get; set; }
        public string ContentEncoded { get; set; }
        public string CoverImageUri { get; set; } 
    }

        private Item ParseItemNode(XElement itemNode)
        {
            var item = new Item();
            item.Title = itemNode.Element("title").Value;
            string uriString = itemNode.Element("link").Value;
            if (string.IsNullOrEmpty(uriString) == false)
            {
                item.Link = new Uri(uriString);
            }
            item.PublishedDate = DateTime.Parse(itemNode.Element("pubDate").Value);

            XNamespace dc = XmlNameSpaceDic["dc"];
            item.Creator = itemNode.Element(dc + "creator").Value;
            item.Category = itemNode.Element("category").Value;
            item.Description = itemNode.Element("description").Value;
            XNamespace content = XmlNameSpaceDic["content"];
            var contentEncoded = itemNode.Element(content + "encoded").Value;
            
            var allImageUri = GetAllImageUri(ref contentEncoded);
            item.CoverImageUri = allImageUri.FirstOrDefault();
            item.ContentEncoded = RemoveEmbedFlash(contentEncoded);
            return item;
        }

        private Dictionary<string, string> GetXmlNameSpaceDic(XElement rssNode)
        {
            var dic = new Dictionary<string, string>();
            foreach (var attribute in rssNode.Attributes().Where(_ => _.IsNamespaceDeclaration))
            {
                dic.Add(attribute.Name.LocalName,attribute.Value);
            }

            return dic;
        }

        private List<string> GetAllImageUri(ref string content)
        {
            var matchList = new List<string>();
            string pattern = "<img.+?src=[\"‘](.+?)[\"‘].*?>";

            var regex = new Regex(pattern, RegexOptions.IgnoreCase);
            foreach (Match match in regex.Matches(content))
            {
                var uri = EditImageUri(match.Value);
                if (uri != match.Value)
                {
                    matchList.Add(match.Groups[1].Value);
                    content = content.Replace(match.Value, uri);
                }
            }

            return matchList;
        }