[C#]Windows RSS Platform

Windows RSS Platform提供RSS訂閱清單、訂閱增減等功能，其RSS的訂閱資訊會整合在7.0以上的IE版本內。

開發時需將Microsoft Feeds 2.0 Object Library這個COM物件加入參考。

加入參考後需將Microsoft.Feeds.Interop命名空間加入，命名空間內含有開發所需要的類別，主要的類別有FeedManager、FeedFolder、Feed、與FeedItem等。FeedManager為主要的管理類別，具備有RootFolder屬性，指向RSS清單的根目錄。FeedFolder為訂閱節點目錄，可透過SubFolders瀏覽內含有子目錄，或是透過Feeds瀏覽所訂閱節點。Feed為訂閱的網站資訊，內含訂閱網站所提供的訂閱內容。FeedItem為訂閱內容，可取得其Title、發佈時間、RSS描述等資訊、與取得設定是否內容是否已讀取。

看到這裡可稍微參閱一下MSDN上的圖片，釐清其彼此間的關聯性並加深印象。

這邊以Windows RSS Platform實做一個簡單的RSS訂閱程式，完整程式範例如下：

using System;  

using System.Drawing;  

using System.Windows.Forms;  

using Microsoft.Feeds.Interop;

namespace WindowsFormsApplication2  

{  

    public partial class MainForm : Form  

    {  

        #region Var  

        private IFeedsManager _feedsManager;  

        private IFeedFolder _rootFolder;  

        #endregion

        #region Property  

        public IFeedsManager m_FeedsManager  

        {  

            get  

            {  

                if (_feedsManager == null)  

                    _feedsManager = new FeedsManagerClass();  

                return _feedsManager;  

            }  

        }

        public IFeedFolder m_RootFolder  

        {  

            get  

            {  

                if (_rootFolder == null)  

                    _rootFolder = (IFeedFolder)m_FeedsManager.RootFolder;  

                return _rootFolder;  

            }  

        }  

        #endregion

        #region Constructor  

        public MainForm()  

        {  

            InitializeComponent();  

        }  

        #endregion

        #region Private Method  

        private void SetFeedNodes()  

        {  

            treeView1.Nodes.Clear();  

            SetFeedNodes(treeView1.Nodes.Add("Feeds"), m_RootFolder);  

        }

        private void SetFeedNodes(TreeNode parentnode, IFeedFolder folder)  

        {  

            if (folder.Subfolders != null)  

            {  

                foreach (IFeedFolder subfolder in (IFeedsEnum)folder.Subfolders)  

                {  

                    SetFeedNodes(parentnode.Nodes.Add(subfolder.Name), subfolder);  

                }  

            }

            if (folder.Feeds != null)  

            {  

                foreach (IFeed feed in (IFeedsEnum)folder.Feeds)  

                {  

                    parentnode.Nodes.Add(feed.Name).Tag = feed;  

                }  

            }  

        }  

        #endregion

        #region Event Process  

        private void Form1_Load(object sender, EventArgs e)  

        {  

            SetFeedNodes();  

            treeView1.ExpandAll();  

        }

        private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)  

        {  

            IFeed feed = e.Node.Tag as IFeed;  

            if (feed == null)  

                return;

            listView1.Items.Clear();  

            webBrowser1.DocumentText = string.Empty;

            var unreadFont = new Font(listView1.Font, FontStyle.Bold);

            foreach (IFeedItem item in (IFeedsEnum)feed.Items)  

            {  

                listView1.Items.Add(new ListViewItem(new string[] { item.Title, item.PubDate.ToShortDateString() })  

                {  

                    Font = (item.IsRead) ? listView1.Font : unreadFont,  

                    Tag = item  

                });  

            }  

        }

        private void listView1_SelectedIndexChanged(object sender, EventArgs e)  

        {  

            if (listView1.SelectedItems.Count == 0 || listView1.SelectedItems[0].Tag == null)  

                return;

            ListViewItem li = listView1.SelectedItems[0];  

            IFeedItem item = li.Tag as IFeedItem;

            if (item == null)  

                return;

            item.IsRead = true;  

            li.Font = listView1.Font;

            webBrowser1.DocumentText = item.Description;  

            if (webBrowser1.DocumentText.Length == 0)  

                webBrowser1.Navigate(item.Link);  

        }

        private void toolStripLabel1_Click(object sender, EventArgs e)  

        {  

            FeedAddDialog dlg = new FeedAddDialog();  

            if (dlg.ShowDialog() == DialogResult.OK)  

            {  

                ((IFeed)m_RootFolder.CreateFeed(dlg.FeedName, dlg.FeedURL)).AsyncDownload();  

                SetFeedNodes();  

                treeView1.ExpandAll();  

            }  

        }

        private void toolStripLabel2_Click(object sender, EventArgs e)  

        {  

            SetFeedNodes();  

            treeView1.ExpandAll();  

        }  

        #endregion  

    }  

}

運行結果如下：

Download

WindowsFormsApplication2.zip

Link

	Accessing the Windows RSS Platform with C#

	Working with the Windows RSS Platform (C#)

	Windows RSS Platform

	Windows RSS Platform Reference

	FeedsManager Object

	Introducing the Windows RSS Platform