在 MVVM 应用程序中使用 RSS feed 加载 Xdocument
我正在学习 MVVM &通过转换简单的 wpf RSS 应用程序来实现 Linq 到 xml。最初，我使用 XmlDataProvider 加载本地 xml 文件或 RSS url。我现在使用下面的代码，它可以很好地加载本地 xml 文件，但在其 url 时抛出“FileNotFoundException”。在调试过程中，我在（字符串 RSS_URL）中看到正确的 url 地址，但未找到该文件。我最初的搜索引导我找到了 Webclient & HttpWebRequest，但我还没有取得任何成功。我走在正确的轨道上吗？有可用的代码或教程链接吗？
public static List<RSSItem> Load(string RSS_URL)
{
if (!File.Exists(RSS_URL))
{
throw new FileNotFoundException("Datasource file could not be found", RSS_URL);
}
var rssfiles = XDocument.Load(RSS_URL).Descendants("item").Select(
x => new RSSItem(
(string)x.Element("title"),
(string)x.Element("link"),
(string)x.Element("description")));
return rssfiles.ToList();
}
谢谢
I am learning MVVM & Linq to xml by converting a simple wpf RSS app. Originally, I used XmlDataProvider to load local xml files or RSS urls. I am now using the code below which works fine loading local xml files, but throws the "FileNotFoundException" when its a url. During debugging I see the correct url address in (string RSS_URL), yet the file is not found. My initial searching led me to Webclient & HttpWebRequest, but I haven't had any success with them. Am I on the right track? Any code or tutorial links available?
public static List<RSSItem> Load(string RSS_URL)
{
if (!File.Exists(RSS_URL))
{
throw new FileNotFoundException("Datasource file could not be found", RSS_URL);
}
var rssfiles = XDocument.Load(RSS_URL).Descendants("item").Select(
x => new RSSItem(
(string)x.Element("title"),
(string)x.Element("link"),
(string)x.Element("description")));
return rssfiles.ToList();
}
Thank You
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（2）
XDocument.Load() 将毫无问题地接受 URL。代码中的问题是您使用 File.Exists() 来确定 URL 是否有效。 File.Exists() 只接受文件系统路径，而不接受 uri。
快速提供一些附加信息：Load() 方法依赖于基础 XmlReader 和对 Create() 的调用。如果资源（本例中为 URL）不存在，则会抛出 WebException，指示资源不存在。
XDocument.加载信息：
http://msdn.microsoft.com/en-us/library/bb343181.aspx
XmlReader.创建信息：
http://msdn.microsoft.com/en-us/library/w8k674bf.aspx
XDocument.Load() will accept URLs without any problem. The issue in your code is that you're using File.Exists() to determine whether or not he URL is valid. File.Exists() only accepts a filesystem path, not a uri.
Quick piece of additional info: the Load() method relies on an underlying XmlReader and a call to Create(). If the resource (the URL in this case) doesn't exist, a WebException will be thrown indicating that the resource doesn't exist.
XDocument.Load info:
http://msdn.microsoft.com/en-us/library/bb343181.aspx
XmlReader.Create info:
http://msdn.microsoft.com/en-us/library/w8k674bf.aspx
您使用的
XDocument.Load重载专门用于从文件加载。您必须从 RSS 源下载才能在本地获取 XML 数据。查看此处的 MSDN 文档替代方案例如从流中读取，这可能更适合您的需要。The
XDocument.Loadoverload you are using is specifically for loading from a file. You would have to download from the RSS feed to get the XML data locally. Look at the MSDN document here for alternatives such as reading from a stream, which might be better suited to what you need.