I added posts from blog to RSS feed. Everything works fine. But I can't show summary of each post. I get the values of each post through below code,

IPublishedContent blog = Model.Content.AncestorOrSelf("SmBlog");

IEnumerable<IPublishedContent> posts = blog.Descendants("SmBlogPost").OrderBy("smBlogDate desc");

Then I write RSS feed as below,

Response.ContentType = "text/xml";

XmlTextWriter feedWriter = new XmlTextWriter(Response.OutputStream, System.Text.Encoding.UTF8);

feedWriter.WriteStartDocument(); feedWriter.WriteStartElement("rss");

feedWriter.WriteAttributeString("version", "2.0");

feedWriter.WriteStartElement("channel");

feedWriter.WriteElementString("title", Model.Content.GetProperty("smBlogRssTitle").Value.ToString());

feedWriter.WriteElementString("description", Model.Content.GetProperty("smBlogRssDescription").Value.ToString());

feedWriter.WriteElementString("copyright", Model.Content.GetProperty("smBlogRssCopyright").Value.ToString());

feedWriter.WriteElementString("pubDate", postDate.ToString("ddd, dd MMMM yyyy HH:mm:ss"));

foreach (dynamic post in posts)

    {

        feedWriter.WriteStartElement("item");

        feedWriter.WriteElementString("title", post.GetPropertyValue("smBlogTitle"));

feedWriter.WriteElementString("description",post.GetPropertyValue("smBlogSummary") );

        feedWriter.WriteElementString("guid", Umbraco.NiceUrlWithDomain(post.Id));

        feedWriter.WriteElementString("pubDate",

Convert.ToDateTime(post.GetPropertyValue("smBlogDate")).ToString("ddd, dd MMMM yyyy HH:mm:ss"));

        feedWriter.WriteEndElement();

    }

   feedWriter.WriteEndElement();    feedWriter.WriteEndElement();

    feedWriter.WriteEndDocument();    feedWriter.Flush();

    feedWriter.Close();    Response.End();

post.GetPropertyValue("smBlogSummary") );  throws error as below,

When I change its data type to 'TextSring' from 'RichTextEditor', it works fine. But I need to display summary with 'RichTextEditor' data type.