今天写了一个简单的新浪新闻RSS操作类库

今天，有位群友问我如何获新浪新闻列表相关问题，我想，用正则表达式网页中取显然既复杂又不一定准确，现在许多大型网站都有RSS集合，所以我就跟他说用RSS应该好办一些。

 

一年前我写过一个RSS阅读器，不过，打新浪相关的XML文件看了一下，发现RSS2.0 和一年前的不大一样了，但具体怎么处理，几句话也很难讲得清楚，所以，我干脆写了一个类库给他，直接调用。

 

类库不是很复杂，主要两个功能：

一、通过新浪的根频道XML在把所有频道的信息读出来，使用递归连同子节点也读取出来。

二、指定频道URL的XML文件来获取新闻信息。

 

首先，我们写两个类，一个用于保存新闻个息，另一个用于保存频道信息。

/// <summary> /// 新闻记录实体 /// </summary> [Serializable] public class NewsItem { /// <summary> /// 新闻标题 /// </summary> public string Title { get; set; } /// <summary> /// 新闻链接 /// </summary> public string Link { get; set; } /// <summary> /// 作者 /// </summary> public string Author { get; set; } /// <summary> /// 分类 /// </summary> public string Category { get; set; } /// <summary> /// 发布时间 /// </summary> public DateTime PubDate { get; set; } /// <summary> /// 描述 /// </summary> public string Description { get; set; } /// <summary> /// 其它说明 /// </summary> public string Comments { get; set; } }

 

/// <summary> /// 新闻频道列表 /// </summary> [Serializable] public class OutLine { /// <summary> /// 频道标题 /// </summary> public string Title { get; set; } /// <summary> /// 频道文本 /// </summary> public string Text { get; set; } /// <summary> /// 频道类型-RSS /// </summary> public string Type { get; set; } /// <summary> /// XML地址 /// </summary> public string xmlUrl { get; set; } /// <summary> /// HTML地址 /// </summary> public string htmlUrl { get; set; } private List<OutLine> _olChildren = new List<OutLine>(); /// <summary> /// 子频道 /// </summary> public List<OutLine> ChildrenOutline { get { return _olChildren; } } }

 

好，接下来对应的两类，分别获取频道列表和新闻列表。

/// <summary> /// 新闻项管理类 /// </summary> public class NewsManager { /// <summary> /// 根据输入的XML地址获取新闻列表。 /// </summary> /// <param name="xmlUrl">新闻频道的XML地址</param> /// <returns>NewsItem的结果集合</returns> public List<NewsItem> GetNewsItemList(string xmlUrl) { List<NewsItem> _myNews = new List<NewsItem>(); XElement myRoot = XElement.Load(xmlUrl); var theItems = from xe in myRoot.Element("channel").Elements("item") select xe; foreach (XElement e in theItems) { _myNews.Add(new NewsItem() { Title = (string)e.Element("title"), Link = (string)e.Element("link"), Author = (string)e.Element("author"), Category = (string)e.Element("category"), PubDate = (DateTime)e.Element("pubDate"), Comments = (string)e.Element("comments"), Description = (string)e.Element("description") }); } return _myNews; } }

 

/// <summary> /// 自动获取频道列表类 /// </summary> public class OutlineManager { /// <summary> /// 获取频道列表，包含子节点 /// </summary> /// <param name="xmlUrl">根频道地址</param> /// <returns></returns> public List<OutLine> GetCannels(string xmlUrl) { List<OutLine> _list = new List<OutLine>(); XElement root = XElement.Load(xmlUrl); var firstOutline = root.Element("body").Elements("outline"); foreach (XElement xitem in firstOutline) { OutLine myRootOutline = new OutLine { Title = (string)xitem.Attribute("title") ?? "", Text = (string)xitem.Attribute("text") ?? "", Type = (string)xitem.Attribute("type") ?? "", xmlUrl = (string)xitem.Attribute("xmlUrl") ?? "", htmlUrl = (string)xitem.Attribute("htmlUrl") ?? "" }; AddChildElements(xitem, myRootOutline); _list.Add(myRootOutline); } return _list; } private void AddChildElements(XElement xNode, OutLine ol) { if (xNode == null) return; var xc = xNode.Elements("outline"); // 递归，添加子节点 foreach (XElement xe in xc) { OutLine outline = new OutLine() { Title = xe.Attribute("title").Value, Text = xe.Attribute("text").Value, Type = xe.Attribute("type").Value, xmlUrl = xe.Attribute("xmlUrl").Value, htmlUrl = xe.Attribute("htmlUrl").Value }; ol.ChildrenOutline.Add(outline); AddChildElements(xe, outline); } } }

 

OK，简单的类库写好了，程序集名称为SinaRssAPIs_CS，然后，我们建一个程序来测试一下。

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using SinaRssAPIs_CS; namespace NewsApiTest { public partial class Form1 : Form { public Form1() { InitializeComponent(); this.WindowState = FormWindowState.Maximized; this.Text = "新浪RSS类库示例程序"; this.treeView1.AfterSelect += new TreeViewEventHandler(treeView1_AfterSelect); this.dataGridView1.AutoGenerateColumns = false; //不自动创建列 //添加列 DataGridViewTextBoxColumn colTitle = new DataGridViewTextBoxColumn(); colTitle.HeaderText = "新闻标题"; colTitle.DataPropertyName = "Title"; this.dataGridView1.Columns.Add(colTitle); DataGridViewTextBoxColumn colDesc = new DataGridViewTextBoxColumn(); colDesc.HeaderText = "描述"; colDesc.DataPropertyName = "Description"; colDesc.Width = 280; this.dataGridView1.Columns.Add(colDesc); DataGridViewTextBoxColumn colDate = new DataGridViewTextBoxColumn(); colDate.DefaultCellStyle.Format = "yyyy-MM-dd"; colDate.HeaderText = "发布日期"; colDate.DataPropertyName = "PubDate"; this.dataGridView1.Columns.Add(colDate); DataGridViewTextBoxColumn colAuthor = new DataGridViewTextBoxColumn(); colAuthor.HeaderText = "发布者"; colAuthor.DataPropertyName = "Author"; this.dataGridView1.Columns.Add(colAuthor); DataGridViewTextBoxColumn colLink = new DataGridViewTextBoxColumn(); colLink.DataPropertyName = "Link"; colLink.Name = "link"; colLink.Visible = false; this.dataGridView1.Columns.Add(colLink); this.dataGridView1.SelectionChanged += new EventHandler(dataGridView1_SelectionChanged); } void dataGridView1_SelectionChanged(object sender, EventArgs e) { if (this.dataGridView1.CurrentRow == null) return; string link = this.dataGridView1.CurrentRow.Cells["link"].Value.ToString(); this.webBrowser1.Navigate(link); } void treeView1_AfterSelect(object sender, TreeViewEventArgs e) { if (e.Node.Tag == null) return; string xml = e.Node.Tag.ToString(); List<NewsItem> items = null; NewsManager mg = new NewsManager(); items = mg.GetNewsItemList(xml); this.dataGridView1.DataSource = items; } private void Form1_Load(object sender, EventArgs e) { OutlineManager omg = new OutlineManager(); List<OutLine> cnList = omg.GetCannels(@"http://rss.sina.com.cn/sina_all_opml.xml"); this.treeView1.BeginUpdate(); this.treeView1.Nodes.Clear(); //根节点 foreach (OutLine root in cnList) { TreeNode tnRoot = new TreeNode(); tnRoot.Text = root.Title.Split('-')[0]; AddNodes(root, tnRoot); this.treeView1.Nodes.Add(tnRoot); } this.treeView1.EndUpdate(); } private void AddNodes(OutLine ol, TreeNode nd) { foreach (OutLine oits in ol.ChildrenOutline) { TreeNode tn = new TreeNode(); tn.Text = oits.Title; tn.Tag = oits.xmlUrl; AddNodes(oits, tn); nd.Nodes.Add(tn); } } } }

大致的运行效果如下：

 

现在，我说一下技术要点，不多，就一个，对，就是LinQ To XML。