如何获得媒体:缩略图从Youtube API在Windows Phone

Question

我正试图从youtube的原子提要中获得缩略图。下面是我的代码:

XNamespace atom = "http://www.w3.org/2005/Atom";
XNamespace media = "http://search.yahoo.com/mrss/";
var YTitems = from entry in document.Descendants(atom + "entry")
              select new RSSFeed
              {
                   Image = entry.Element(media + "thumbnail").Attribute("url").Value,
                   Title = entry.Element(atom + "title").Value,
                   Description = entry.Element(atom + "content").Value
              };
YoutubeList.ItemsSource = YTitems.ToList();

但是当尝试加载提要时，我得到这个错误:

NullReferenceException was unhandled by user code
Object reference not set to an instance of an object

没有"Image = entry.element(......"也可以工作，所以问题可能在那里。(此处为提要示例)

Answer 1

我修复了这个问题:

ImageSRC = entry.Element(media + "group").Element(media + "thumbnail").Attribute("url").Value