Error_1_Inconsistent accessibility: property type 'System.Collections.ObjectModel.ObservableCollection WindowsBlogReader.FeedData ' is less accessible than property 'WindowsBlogReader.FeedDataSource.Feeds'

Question

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.Web.Syndication;
namespace WindowsBlogReader
   public class FeedData
        public string Title { get; set; }
        public string Description { get; set; }
        public DateTime PubDate { get; set; }
        private List<FeedItem> _Items = new List<FeedItem>();
        public List<FeedItem> Items
            get
                return this._Items;
    // FeedItem
    // Holds info for a single blog post.
    public class FeedItem
        public string Title { get; set; }
        public string Author { get; set; }
        public string Content { get; set; }
        public DateTime PubDate { get; set; }
        public Uri Link { get; set; }
    // FeedDataSource
    // Holds a collection of blog feeds (FeedData), and contains methods needed to
    // retreive the feeds.
    public class FeedDataSource
        private ObservableCollection<FeedData> _Feeds = new ObservableCollection<FeedData>();
        public ObservableCollection<FeedData> Feeds         //Error Here//
            get
                return this._Feeds;
        public async Task GetFeedsAsync()
            Task<FeedData> feed1 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/developers/atom.aspx");
            Task<FeedData> feed2 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/windowsexperience/atom.aspx");
            Task<FeedData> feed3 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/extremewindows/atom.aspx");
            Task<FeedData> feed4 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/business/atom.aspx");
            Task<FeedData> feed5 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/bloggingwindows/atom.aspx");
            Task<FeedData> feed6 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/windowssecurity/atom.aspx");
            Task<FeedData> feed7 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/springboard/atom.aspx");
            Task<FeedData> feed8 =
                GetFeedAsync("http://windowsteamblog.com/windows/b/windowshomeserver/atom.aspx");
            // There is no Atom feed for this blog, so use the RSS feed.
            Task<FeedData> feed9 =
                GetFeedAsync("http://windowsteamblog.com/windows_live/b/windowslive/rss.aspx");
            Task<FeedData> feed10 =
                GetFeedAsync("http://windowsteamblog.com/windows_live/b/developer/atom.aspx");
            Task<FeedData> feed11 =
                GetFeedAsync("http://windowsteamblog.com/ie/b/ie/atom.aspx");
            Task<FeedData> feed12 =
                GetFeedAsync("http://windowsteamblog.com/windows_phone/b/wpdev/atom.aspx");
            Task<FeedData> feed13 =
                GetFeedAsync("http://windowsteamblog.com/windows_phone/b/wmdev/atom.aspx");
            Task<FeedData> feed14 =
                GetFeedAsync("http://windowsteamblog.com/windows_phone/b/windowsphone/atom.aspx");
            this.Feeds.Add(await feed1);
            this.Feeds.Add(await feed2);
            this.Feeds.Add(await feed3);
            this.Feeds.Add(await feed4);
            this.Feeds.Add(await feed5);
            this.Feeds.Add(await feed6);
            this.Feeds.Add(await feed7);
            this.Feeds.Add(await feed8);
            this.Feeds.Add(await feed9);
            this.Feeds.Add(await feed10);
            this.Feeds.Add(await feed11);
            this.Feeds.Add(await feed12);
            this.Feeds.Add(await feed13);
            this.Feeds.Add(await feed14);
        private async Task<FeedData> GetFeedAsync(string feedUriString)
            Windows.Web.Syndication.SyndicationClient client = new SyndicationClient();
            Uri feedUri = new Uri(feedUriString);
            try
                SyndicationFeed feed = await client.RetrieveFeedAsync(feedUri);
                // This code is executed after RetrieveFeedAsync returns the SyndicationFeed.
                // Process the feed and copy the data you want into the FeedData and FeedItem classes.
                FeedData feedData = new FeedData();
                if (feed.Title != null && feed.Title.Text != null)
                    feedData.Title = feed.Title.Text;
                if (feed.Subtitle != null && feed.Subtitle.Text != null)
                    feedData.Description = feed.Subtitle.Text;
                if (feed.Items != null && feed.Items.Count > 0)
                    // Use the date of the latest post as the last updated date.
                    feedData.PubDate = feed.Items[0].PublishedDate.DateTime;
                    foreach (SyndicationItem item in feed.Items)
                        FeedItem feedItem = new FeedItem();
                        if (item.Title != null && item.Title.Text != null)
                            feedItem.Title = item.Title.Text;
                        if (item.PublishedDate != null)
                            feedItem.PubDate = item.PublishedDate.DateTime;
                        if (item.Authors != null && item.Authors.Count > 0)
                            feedItem.Author = item.Authors[0].Name.ToString();
                        // Handle the differences between RSS and Atom feeds.
                        if (feed.SourceFormat == SyndicationFormat.Atom10)
                            if (item.Content != null && item.Content.Text != null)
                                feedItem.Content = item.Content.Text;
                            if (item.Id != null)
                                feedItem.Link = new Uri("http://windowsteamblog.com" + item.Id);
                        else if (feed.SourceFormat == SyndicationFormat.Rss20)
                            if (item.Summary != null && item.Summary.Text != null)
                                feedItem.Content = item.Summary.Text;
                            if (item.Links != null && item.Links.Count > 0)
                                feedItem.Link = item.Links[0].Uri;
                        feedData.Items.Add(feedItem);
                return feedData;
            catch (Exception)
                return null;
        // Returns the feed that has the specified title.
        public static FeedData GetFeed(string title)             //ERROR HERE
            // Simple linear search is acceptable for small data sets
            var _feedDataSource = App.Current.Resources["feedDataSource"] as FeedDataSource;
            var matches = _feedDataSource.Feeds.Where((feed) => feed.Title.Equals(title));
            if (matches.Count() == 1) return matches.First();
            FeedData feeddata = null;
            return feeddata;
        // Returns the post that has the specified title.
        public static FeedItem GetItem(string uniqueId)
            // Simple linear search is acceptable for small data sets
            var _feedDataSource = App.Current.Resources["feedDataSource"] as FeedDataSource;
            var _feeds = _feedDataSource.Feeds;
            var matches = _feedDataSource.Feeds.SelectMany(group => group.Items).Where((item) => item.Title.Equals(uniqueId));
            if (matches.Count() == 1) return matches.First();
            return null;
}

Answer 1

The feed links given in the msdn site are already broken because now the official site for windows blogs is "blogs.windows.com" & not "windowsteamblogs.com". I am posting the updated code here :-
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Threading.Tasks;
using Windows.Web.Syndication;
namespace WindowsBlogReader
// FeedData
// Holds info for a single blog feed, including a list of blog posts (FeedItem).
public class FeedData
public string Title { get; set; }
public string Description { get; set; }
public DateTime PubDate { get; set; }
private List<FeedItem> _Items = new List<FeedItem>();
public List<FeedItem> Items
get
return this._Items;
// FeedItem
// Holds info for a single blog post.
public class FeedItem
public string Title { get; set; }
public string Author { get; set; }
public string Content { get; set; }
public DateTime PubDate { get; set; }
public Uri Link { get; set; }
// FeedDataSource
// Holds a collection of blog feeds (FeedData), and contains methods needed to
// retreive the feeds.
public class FeedDataSource
private ObservableCollection<FeedData> _Feeds = new ObservableCollection<FeedData>();
public ObservableCollection<FeedData> Feeds
get
return this._Feeds;
public async Task GetFeedsAsync()
#region WindowsTeamBlogs Feed Links
//Task<FeedData> feed1 =
// GetFeedAsync("http://windowsteamblog.com/windows/b/developers/atom.aspx");
//Task<FeedData> feed2 =
// GetFeedAsync("http://windowsteamblog.com/windows/b/windowsexperience/atom.aspx");
//Task<FeedData> feed3 =
// GetFeedAsync("http://windowsteamblog.com/windows/b/extremewindows/atom.aspx");
//Task<FeedData> feed4 =
// GetFeedAsync("http://windowsteamblog.com/windows/b/business/atom.aspx");
//Task<FeedData> feed5 =
// GetFeedAsync("http://windowsteamblog.com/windows/b/bloggingwindows/atom.aspx");
//Task<FeedData> feed6 =
// GetFeedAsync("http://windowsteamblog.com/windows/b/windowssecurity/atom.aspx");
//Task<FeedData> feed7 =
// GetFeedAsync("http://windowsteamblog.com/windows/b/springboard/atom.aspx");
//Task<FeedData> feed8 =
// GetFeedAsync("http://windowsteamblog.com/windows/b/windowshomeserver/atom.aspx");
//// There is no Atom feed for this blog, so use the RSS feed.
//Task<FeedData> feed9 =
// GetFeedAsync("http://windowsteamblog.com/windows_live/b/windowslive/rss.aspx");
//Task<FeedData> feed10 =
// GetFeedAsync("http://windowsteamblog.com/windows_live/b/developer/atom.aspx");
//Task<FeedData> feed11 =
// GetFeedAsync("http://windowsteamblog.com/ie/b/ie/atom.aspx");
//Task<FeedData> feed12 =
// GetFeedAsync("http://windowsteamblog.com/windows_phone/b/wpdev/atom.aspx");
//Task<FeedData> feed13 =
// GetFeedAsync("http://windowsteamblog.com/windows_phone/b/wmdev/atom.aspx");
//Task<FeedData> feed14 =
// GetFeedAsync("http://windowsteamblog.com/windows_phone/b/windowsphone/atom.aspx");
#endregion
#region Windows Blogs Broken Links
//Task<FeedData> feed1 =
// GetFeedAsync("http://blogs.windows.com/skydrive/b/skydrive/atom.aspx");
//Task<FeedData> feed2 =
// GetFeedAsync("http://blogs.windows.com/windows/b/windowsexperience/atom.aspx");
//Task<FeedData> feed3 =
// GetFeedAsync("http://blogs.windows.com/windows/b/extremewindows/atom.aspx");
//Task<FeedData> feed4 =
// GetFeedAsync("http://blogs.windows.com/windows/b/business/atom.aspx");
//Task<FeedData> feed5 =
// GetFeedAsync("http://blogs.windows.com/windows/b/bloggingwindows/atom.aspx");
//Task<FeedData> feed6 =
// GetFeedAsync("http://blogs.windows.com/windows/b/windowssecurity/atom.aspx");
//Task<FeedData> feed7 =
// GetFeedAsync("http://blogs.windows.com/windows/b/springboard/atom.aspx");
//Task<FeedData> feed8 =
// GetFeedAsync("http://blogs.windows.com/windows/b/windowshomeserver/atom.aspx");
//// There is no Atom feed for this blog, so use the RSS feed.
//Task<FeedData> feed9 =
// GetFeedAsync("http://blogs.windows.com/windows_live/b/windowslive/rss.aspx");
//Task<FeedData> feed10 =
// GetFeedAsync("http://blogs.windows.com/windows_live/b/developer/atom.aspx");
//Task<FeedData> feed11 =
// GetFeedAsync("http://blogs.windows.com/ie/b/ie/atom.aspx");
//Task<FeedData> feed12 =
// GetFeedAsync("http://blogs.windows.com/windows_phone/b/wpdev/atom.aspx");
//Task<FeedData> feed13 =
// GetFeedAsync("http://blogs.windows.com/windows_phone/b/wmdev/atom.aspx");
//Task<FeedData> feed14 =
// GetFeedAsync("http://blogs.windows.com/windows_phone/b/windowsphone/atom.aspx");
#endregion
#region Windows Blogs Feeds
Task<FeedData> feed1 =
GetFeedAsync("http://blogs.windows.com/windows/b/bloggingwindows/rss.aspx");
Task<FeedData> feed2 =
GetFeedAsync("http://blogs.windows.com/windows/b/windowsexperience/rss.aspx");
Task<FeedData> feed3 =
GetFeedAsync("http://blogs.windows.com/windows/b/extremewindows/rss.aspx");
Task<FeedData> feed4 =
GetFeedAsync("http://blogs.windows.com/windows/b/business/rss.aspx");
Task<FeedData> feed5 =
GetFeedAsync("http://blogs.windows.com/windows/b/windowssecurity/rss.aspx");
Task<FeedData> feed6 =
GetFeedAsync("http://blogs.windows.com/windows/b/springboard/rss.aspx");
Task<FeedData> feed7 =
GetFeedAsync("http://blogs.windows.com/windows/b/windowshomeserver/rss.aspx");
Task<FeedData> feed8 =
GetFeedAsync("http://blogs.windows.com/windows_live/b/windowslive/rss.aspx");
Task<FeedData> feed9 =
GetFeedAsync("http://blogs.windows.com/windows_live/b/developer/rss.aspx");
Task<FeedData> feed10 =
GetFeedAsync("http://blogs.windows.com/ie/b/ie/rss.aspx");
Task<FeedData> feed11 =
GetFeedAsync("http://blogs.windows.com/skydrive/b/skydrive/rss.aspx");
Task<FeedData> feed12 =
GetFeedAsync("http://blogs.windows.com/windows_phone/b/windowsphone/rss.aspx");
Task<FeedData> feed13 =
GetFeedAsync("http://blogs.windows.com/windows_phone/b/wpdev/rss.aspx");
Task<FeedData> feed14 =
GetFeedAsync("http://blogs.windows.com/windows_phone/b/wmdev/rss.aspx");
#endregion
#region Downloading the Feeds
this.Feeds.Add(await feed1);
this.Feeds.Add(await feed2);
this.Feeds.Add(await feed3);
this.Feeds.Add(await feed4);
this.Feeds.Add(await feed5);
this.Feeds.Add(await feed6);
this.Feeds.Add(await feed7);
this.Feeds.Add(await feed8);
this.Feeds.Add(await feed9);
this.Feeds.Add(await feed10);
this.Feeds.Add(await feed11);
this.Feeds.Add(await feed12);
this.Feeds.Add(await feed13);
this.Feeds.Add(await feed14);
#endregion
private async Task<FeedData> GetFeedAsync(string feedUriString)
Windows.Web.Syndication.SyndicationClient client = new SyndicationClient();
Uri feedUri = new Uri(feedUriString);
try
SyndicationFeed feed = await client.RetrieveFeedAsync(feedUri);
// This code is executed after RetrieveFeedAsync returns the SyndicationFeed.
// Process the feed and copy the data you want into the FeedData and FeedItem classes.
FeedData feedData = new FeedData();
if (feed.Title != null && feed.Title.Text != null)
feedData.Title = feed.Title.Text;
if (feed.Subtitle != null && feed.Subtitle.Text != null)
feedData.Description = feed.Subtitle.Text;
if (feed.Items != null && feed.Items.Count > 0)
// Use the date of the latest post as the last updated date.
feedData.PubDate = feed.Items[0].PublishedDate.DateTime;
foreach (SyndicationItem item in feed.Items)
FeedItem feedItem = new FeedItem();
if (item.Title != null && item.Title.Text != null)
feedItem.Title = item.Title.Text;
if (item.PublishedDate != null)
feedItem.PubDate = item.PublishedDate.DateTime;
if (item.Authors != null && item.Authors.Count > 0)
feedItem.Author = item.Authors[0].Name.ToString();
// Handle the differences between RSS and Atom feeds.
if (feed.SourceFormat == SyndicationFormat.Atom10)
if (item.Content != null && item.Content.Text != null)
feedItem.Content = item.Content.Text;
if (item.Id != null)
feedItem.Link = new Uri("http://windowsteamblog.com" + item.Id);
else if (feed.SourceFormat == SyndicationFormat.Rss20)
if (item.Summary != null && item.Summary.Text != null)
feedItem.Content = item.Summary.Text;
if (item.Links != null && item.Links.Count > 0)
feedItem.Link = item.Links[0].Uri;
feedData.Items.Add(feedItem);
return feedData;
catch (Exception)
return null;
// Returns the feed that has the specified title.
public static FeedData GetFeed(string title)
// Simple linear search is acceptable for small data sets
var _feedDataSource = App.Current.Resources["feedDataSource"] as FeedDataSource;
//var matches = _feedDataSource.Feeds.Where((feed) => feed.Title.Equals(title));
var matches = _feedDataSource.Feeds.Where((feed) => feed != null && feed.Title.Equals(title));
if (matches.Count() == 1) return matches.First();
return null;
// Returns the post that has the specified title.
public static FeedItem GetItem(string uniqueId)
// Simple linear search is acceptable for small data sets
var _feedDataSource = App.Current.Resources["feedDataSource"] as FeedDataSource;
var _feeds = _feedDataSource.Feeds;
//var matches = _feedDataSource.Feeds.SelectMany(group => group.Items).Where((item) => item.Title.Equals(uniqueId));
var matches = _feedDataSource.Feeds.SelectMany(group => group.Items).Where((item) => item != null && item.Title.Equals(uniqueId));
if (matches.Count() == 1) return matches.First();
return null;
U will notice that there are 3 sets of list available here.
The first set of links contain the old broken links from  "windowsteamblogs.com",
the second set of links contain the links from  "blogs.windows.com" which are now also broken,
the last set of links contain the links from  "blogs.windows.com" some of which are also broken.
So if u run the program using those links u will get a "nullpointerexception" error.
To solve this problem i updated a line of code in the "GetFeed" method from :- 
var matches = _feedDataSource.Feeds.Where((feed) => feed.Title.Equals(title));
to :- 
var matches = _feedDataSource.Feeds.Where((feed) => feed != null && feed.Title.Equals(title));
This line of code will ignore those empty(null) feeds.
For safety sake i also updated the code in the "GetItem" method, and this "FeedDataSource" class will compile without any error, but he program will crash in split.xaml without giving any proper
error message.
Here are some of the links where people have faced similar problems :- 
Runtime
Error
Parsing
null feeds
Problem
in Page Navigation