C# HtmlNode.GetAttributeValue方法代码示例

		public async Task<HtmlNode> VisitAsync(VisitingContext context, HtmlNode node)
		{
			// We're only interested in stylesheets.
			if (node.GetAttributeValue("rel", null) != "stylesheet")
				return node;
			var href = node.GetAttributeValue("href", null);
			if (href == null)
				return node;
			var hrefUri = new Uri(href, UriKind.RelativeOrAbsolute);
			if (!hrefUri.IsAbsoluteUri)
			{
				hrefUri = new Uri(context.Address, hrefUri);
			}

			// Get the stylesheet and insert it inline.
			var content = default(string);
			try
			{
				content = await context.WebClient.DownloadAsync(hrefUri);
			}
			catch (WebException)
			{
				return node;
			}
			content = "<style>" + content + "</style>";
			return HtmlNode.CreateNode(content);
		}

        /// <summary>
        /// 
        /// </summary>
        /// <param name="formNode"></param>
        /// <param name="session"></param>
        /// <param name="baseUrl"></param>
        /// <param name="charset">The character set used in the previoius response (from which the form originates).</param>
        public Form(HtmlNode formNode, ISession session, Uri baseUrl, string charset)
        {
            Condition.Requires(formNode, "formNode").IsNotNull();
              Condition.Requires(session, "session").IsNotNull();
              Condition.Requires(baseUrl, "baseUrl").IsNotNull();

              if (!formNode.Name.Equals("form", StringComparison.OrdinalIgnoreCase))
            throw new ArgumentException(string.Format("Cannot create HTML form from '{0}' node.", formNode.Name));

              Action = new Uri(baseUrl, formNode.GetAttributeValue("action", ""));
              Method = formNode.GetAttributeValue("method", "get");
              Session = session;
              BaseUrl = baseUrl;
              ResponseCharset = charset;

              string enctype = formNode.GetAttributeValue("enctype", null);
              EncodingType = (enctype != null ? new MediaType(enctype) : MediaType.ApplicationFormUrlEncoded);

              AcceptCharset = formNode.GetAttributeValue("accept-charset", null);

              Values = new Hashtable();
              SubmitElements = new List<SubmitElement>();

              ParseInputs(formNode);
        }

        public bool SetValue(HtmlNode n, string value)
        {
            if (n is HtmlNode && n.Name == "select")
            {
                foreach (HtmlNode o in n.SelectNodes("option"))
                {
                    o.SetAttributeValue("selected", o.GetAttributeValue("value", "").Equals(value) ? "selected" : "");
                }
                return true;
            }

            if (n is HtmlNode && n.Name == "input")
            {
                switch (n.GetAttributeValue("type", ""))
                {
                    case "radio":
                        n.SetAttributeValue("checked", n.GetAttributeValue("value", "").Equals(value) ? "checked" : "");
                        break;
                    default:
                        n.SetAttributeValue("value", value);
                        break;
                }
                n.SetAttributeValue("value", value);
                return true;
            }

            return false;
        }

 private static int GetPageNumber(HtmlNode threadNode)
 {
     if (threadNode != null && !string.IsNullOrEmpty(threadNode.GetAttributeValue("value", string.Empty)))
     {
         return Convert.ToInt32(threadNode.GetAttributeValue("value", string.Empty));
     }
     return 1;
 }

        public override string Convert(HtmlNode node)
        {
            string alt = node.GetAttributeValue("alt", string.Empty);
            string src = node.GetAttributeValue("src", string.Empty);
            string title = this.ExtractTitle(node);

            title = title.Length > 0 ? string.Format(" \"{0}\"", title) : "";

            return string.Format("![{0}]({1}{2})", alt, src, title);
        }

 public static Note Parse(HtmlNode Node)
 {
     string Grade = Node.InnerText.Trim();
     string Name = Node.GetAttributeValue("title", "Névtelen jegy");
     string Href = Node.GetAttributeValue("href", "");
     Match Match = Regex.Match(Href, "jegyId=(?<id>[0-9]+)", RegexOptions.IgnoreCase);
     int ID = int.Parse(Match.Groups["id"].Value);
     string T = Node.GetAttributeValue("class", "jegy2");
     NoteType Type = (NoteType)(int.Parse(T.Substring(T.Length - 1, 1)));
     return new Note(ID, Grade, Name, Type);
 }

 public static string GetTargetFromFilter(HtmlNode node, IFilter filter)
 {
     switch (filter.GetNodeType())
     {
         case NodeType.Image:
             return node.GetAttributeValue("src", "");
         case NodeType.Link:
             return node.GetAttributeValue("href", "");
         default:
             return "";
     }
 }

		static AnchorAnalysis AnalyseAnchor(HtmlNode anchor)
		{
			var href = anchor.GetAttributeValue("href", null);
			var rel = anchor.GetAttributeValue("rel", null);
			var title = anchor.GetAttributeValue("title", null);
			var text = anchor.InnerText;

			// todo: determine if its an offsite link?
			// determine if it contains a title, has text - if not, image? adivse

			return new AnchorAnalysis(text, title, href, rel, new Message[0]);
		}

        /// <summary>
        ///     Parses a forum post in a thread.
        /// </summary>
        /// <param name="postNode">The post HTML node.</param>
        public void Parse(HtmlNode postNode)
        {
            User = ForumUserEntity.FromPost(postNode);

            HtmlNode postDateNode =
                postNode.Descendants()
                    .FirstOrDefault(node => node.GetAttributeValue("class", string.Empty).Equals("postdate"));
            string postDateString = postDateNode == null ? string.Empty : postDateNode.InnerText;
            if (postDateString != null)
            {
                PostDate = postDateString.WithoutNewLines().Trim();
            }

            PostIndex = ParseInt(postNode.GetAttributeValue("data-idx", string.Empty));

            var postId = postNode.GetAttributeValue("id", string.Empty);
            if (!string.IsNullOrEmpty(postId) && postId.Contains("#"))
            {
                PostId =
                    Int64.Parse(postNode.GetAttributeValue("id", string.Empty)
                        .Replace("post", string.Empty)
                        .Replace("#", string.Empty));
            }
            else if (!string.IsNullOrEmpty(postId) && postId.Contains("post"))
            {
                PostId =
                    Int64.Parse(postNode.GetAttributeValue("id", string.Empty)
                        .Replace("post", string.Empty));
            }
            else
            {
                PostId = 0;
            }
         
            var postBodyNode = postNode.Descendants("td")
                .FirstOrDefault(node => node.GetAttributeValue("class", string.Empty).Equals("postbody"));
            this.FixQuotes(postBodyNode);
            PostHtml = postBodyNode.InnerHtml;
            HtmlNode profileLinksNode =
                    postNode.Descendants("td")
                        .FirstOrDefault(node => node.GetAttributeValue("class", string.Empty).Equals("postlinks"));
            HtmlNode postRow =
                postNode.Descendants("tr").FirstOrDefault();

            if (postRow != null)
            {
                HasSeen = postRow.GetAttributeValue("class", string.Empty).Contains("seen");
            }

            User.IsCurrentUserPost =
                profileLinksNode.Descendants("img")
                    .FirstOrDefault(node => node.GetAttributeValue("alt", string.Empty).Equals("Edit")) != null;
        }

        private bool ClassesMatches(HtmlNode node)
        {
            if (classes == null || classes.Length < 1)
            {
                return true;
            }

            string classString;

            if ((classString = node.GetAttributeValue("class", null)) != null)
            {
                string[] nodeClasses = classString.Split(' ');
                if (nodeClasses.Length <= 0) return false;
                bool allMatch = false;
                foreach (string filterClass in classes)
                {
                    bool localMatch = false;
                    foreach (string nodeClass in nodeClasses)
                    {
                        if (filterClass == nodeClass)
                        {
                            localMatch = true;
                        }
                    }
                    allMatch = localMatch;
                }
                return allMatch;
            }
            return false;
        }

 private string GetLanguageFromHighlightClassAttribute(HtmlNode node)
 {
     string val = node.GetAttributeValue("class", "");
     var rx = new System.Text.RegularExpressions.Regex("highlight-([a-zA-Z0-9]+)");
     var res = rx.Match(val);
     return res.Success ? res.Value : "";
 }

        /// <summary>
        /// Parses a thread HTML node to extract the information from it.
        /// </summary>
        /// <param name="threadNode">The thread HTML node.</param>
        public void Parse(HtmlNode threadNode)
        {
            this.Name = WebUtility.HtmlDecode(threadNode.Descendants("a").FirstOrDefault(node => node.GetAttributeValue("class", string.Empty).Equals("thread_title")).InnerText);

            this.KilledBy = threadNode.Descendants("a").LastOrDefault(node => node.GetAttributeValue("class", string.Empty).Equals("author")).InnerText;
            this.IsSticky = threadNode.Descendants("td").Any(node => node.GetAttributeValue("class", string.Empty).Contains("title_sticky"));
            this.IsLocked = threadNode.GetAttributeValue("class", string.Empty).Contains("closed");
            this.CanMarkAsUnread = threadNode.Descendants("a").Any(node => node.GetAttributeValue("class", string.Empty).Equals("x"));
            this.HasBeenViewed = this.CanMarkAsUnread;
            this.Author = threadNode.Descendants("td").FirstOrDefault(node => node.GetAttributeValue("class", string.Empty).Equals("author")).InnerText;
            if (threadNode.Descendants("a").Any(node => node.GetAttributeValue("class", string.Empty).Equals("count")))
            {
                this.RepliesSinceLastOpened = Convert.ToInt32(threadNode.Descendants("a").FirstOrDefault(node => node.GetAttributeValue("class", string.Empty).Equals("count")).InnerText);
            }
            if (threadNode.Descendants("td").Any(node => node.GetAttributeValue("class", string.Empty).Contains("replies")))
            {
                this.ReplyCount = Convert.ToInt32(threadNode.Descendants("td").FirstOrDefault(node => node.GetAttributeValue("class", string.Empty).Contains("replies")).InnerText);
            }
            else
            {
                this.ReplyCount = 1;
            }

            // Isn't this user configurable?
            this.TotalPages = (this.ReplyCount / 40) + 1;
            this.Location = Constants.BASE_URL + threadNode.Descendants("a").FirstOrDefault(node => node.GetAttributeValue("class", string.Empty).Equals("thread_title")).GetAttributeValue("href",string.Empty) + Constants.PER_PAGE;
            this.ThreadId = Convert.ToInt64(threadNode.Descendants("a").FirstOrDefault(node => node.GetAttributeValue("class", string.Empty).Equals("thread_title")).GetAttributeValue("href",string.Empty).Split('=')[1]);
            this.ImageIconLocation = threadNode.Descendants("td").FirstOrDefault(node => node.GetAttributeValue("class", string.Empty).Equals("icon")).Descendants("img").FirstOrDefault().GetAttributeValue("src", string.Empty);
        }

 public StineLinkTreeNode(HtmlNode node)
 {
     base.Text = HttpUtility.HtmlDecode(node.InnerHtml);
     URL = node.GetAttributeValue("href", "not_found");
     URL = HttpUtility.HtmlDecode(URL);
     HTML_NODE = node;
 }

		public async Task<HtmlNode> VisitAsync(VisitingContext context, HtmlNode node)
		{
			var src = node.GetAttributeValue("src", null);
			if (src == null)
				return node;

			// Take care if the src starts with two slashes.
			if (src.StartsWith("//"))
			{
				src = "http:" + src;
			}

			var srcUri = new Uri(src, UriKind.RelativeOrAbsolute);
			if (!srcUri.IsAbsoluteUri)
			{
				srcUri = new Uri(context.Address, srcUri);
			}

			// Get the script and insert it inline.
			var content = default(string);
			try
			{
				content = await context.WebClient.DownloadAsync(srcUri);
			}
			catch (WebException)
			{
				return node;
			}
			content = "<script>" + content + "</script>";
			return HtmlNode.CreateNode(content);
		}

 private static bool IsUnwantedLanguageDiv(HtmlNode div)
 {
     return div.GetAttributeValue("class", "").Equals("libCScode")
            &&
            !div.Element("div").Element("div").InnerText.Trim().Equals("c#",
                                                                       StringComparison.CurrentCultureIgnoreCase);
 }