C# XDocument.GetElementsByTagName方法代码示例

        internal IEnumerable<XElement> FindCandidatesForArticleContent(XDocument document)
        {
            var paraElements = document.GetElementsByTagName("p");
              var candidateElements = new HashSet<XElement>();

              _elementsScores.Clear();

              foreach (var paraElement in paraElements)
              {
            string innerText = GetInnerText(paraElement);

            if (innerText.Length < _MinParagraphLength)
            {
              continue;
            }

            var parentElement = paraElement.Parent;
            var grandParentElement = parentElement != null ? parentElement.Parent : null;
            int score = 1; // 1 point for having a paragraph

            // Add points for any comma-segments within this paragraph.
            score += GetSegmentsCount(innerText, ',');

            // For every PARAGRAPH_SEGMENT_LENGTH characters in this paragraph, add another point. Up to MAX_POINTS_FOR_SEGMENTS_COUNT points.
            score += Math.Min(innerText.Length / _ParagraphSegmentLength, _MaxPointsForSegmentsCount);

            // Add the score to the parent.
            if (parentElement != null && (parentElement.Name == null || !"html".Equals(parentElement.Name.LocalName, StringComparison.OrdinalIgnoreCase)))
            {
              candidateElements.Add(parentElement);
              AddPointsToElementScore(parentElement, score);
            }

            // Add half the score to the grandparent.
            if (grandParentElement != null && (grandParentElement.Name == null || !"html".Equals(grandParentElement.Name.LocalName, StringComparison.OrdinalIgnoreCase)))
            {
              candidateElements.Add(grandParentElement);
              AddPointsToElementScore(grandParentElement, score / 2);
            }
              }

              return candidateElements;
        }

        private static void ResolveElementsUrls(XDocument document, string tagName, string attributeName, string url, Func<AttributeTransformationInput, AttributeTransformationResult> attributeValueTransformer)
        {
            if (document == null)
              {
            throw new ArgumentNullException("document");
              }

              if (string.IsNullOrEmpty(url))
              {
            throw new ArgumentNullException("url");
              }

              var elements = document.GetElementsByTagName(tagName);

              foreach (var element in elements)
              {
            var attributeValue = element.GetAttributeValue(attributeName, null);

            if (attributeValue == null)
            {
              continue;
            }

            attributeValue = ResolveElementUrl(attributeValue, url);

            if (!string.IsNullOrEmpty(attributeValue))
            {
              AttributeTransformationResult attributeTransformationResult;

              if (attributeValueTransformer != null)
              {
            attributeTransformationResult = attributeValueTransformer.Invoke(new AttributeTransformationInput { AttributeValue = attributeValue, Element = element });
              }
              else
              {
            attributeTransformationResult = new AttributeTransformationResult { TransformedValue = attributeValue };
              }

              element.SetAttributeValue(attributeName, attributeTransformationResult.TransformedValue);

              if (!string.IsNullOrEmpty(attributeTransformationResult.OriginalValueAttributeName))
              {
            element.SetAttributeValue(attributeTransformationResult.OriginalValueAttributeName, attributeValue);
              }
            }
              }
        }

        internal void GlueDocument(XDocument document, XElement articleTitleElement, XElement articleContentElement)
        {
            var documentBody = GetOrCreateBody(document);

              /* Include readability.css stylesheet. */
              var headElement = document.GetElementsByTagName("head").FirstOrDefault();

              if (headElement == null)
              {
            headElement = new XElement("head");
            documentBody.AddBeforeSelf(headElement);
              }

              var styleElement = new XElement("style");

              styleElement.SetAttributeValue("type", "text/css");

              var readabilityStylesheetStream = Assembly.GetExecutingAssembly().GetManifestResourceStream(_ReadabilityStylesheetResourceName);

              if (readabilityStylesheetStream == null)
              {
            throw new InternalErrorException("Couldn't load the NReadability stylesheet embedded resource.");
              }

              using (var sr = new StreamReader(readabilityStylesheetStream))
              {
            styleElement.SetInnerHtml(sr.ReadToEnd());
              }

              headElement.Add(styleElement);

              /* Apply reading style to body. */
              string readingStyleClass = GetReadingStyleClass(_readingStyle);

              documentBody.SetClass(readingStyleClass);
              documentBody.SetStyle("display: block;");

              /* Create inner div. */
              var innerDiv = new XElement("div");

              innerDiv.SetId(InnerDivId);
              innerDiv.SetClass(GetReadingMarginClass(_readingMargin) + " " + GetReadingSizeClass(_readingSize));

              if (articleTitleElement != null)
              {
            innerDiv.Add(articleTitleElement);
              }

              if (articleContentElement != null)
              {
            innerDiv.Add(articleContentElement);
              }

              /* Create overlay div. */
              var overlayDiv = new XElement("div");

              overlayDiv.SetId(OverlayDivId);
              overlayDiv.SetClass(readingStyleClass);
              overlayDiv.Add(innerDiv);

              /* Clear the old HTML, insert the new content. */
              documentBody.RemoveAll();
              documentBody.Add(overlayDiv);
        }

        private static XElement TryFindArticleContentElement(XDocument document, string articleContentElementHint)
        {
            if (document == null)
              {
            throw new ArgumentNullException("document");
              }

              if (string.IsNullOrEmpty(articleContentElementHint))
              {
            throw new ArgumentException("Argument can't be null nor empty.", "articleContentElementHint");
              }

              return document
            .GetElementsByTagName(articleContentElementHint)
            .FirstOrDefault();
        }

        internal void GlueDocument(XDocument document, XElement articleTitleElement, XElement articleContentElement)
        {
            XElement documentBody = GetOrCreateBody(document);

              /* Include readability.css stylesheet. */
              XElement headElement = document.GetElementsByTagName("head").FirstOrDefault();

              if (headElement == null)
              {
            headElement = new XElement("head");
            documentBody.AddBeforeSelf(headElement);
              }

              XElement styleElement = new XElement("style");

              styleElement.SetAttributeValue("type", "text/css");

              Stream readabilityStylesheetStream = typeof(NReadabilityTranscoder).GetTypeInfo().Assembly.GetManifestResourceStream(_ReadabilityStylesheetResourceName);

              if (readabilityStylesheetStream == null)
              {
            throw new InternalErrorException("Couldn't load the NReadability stylesheet embedded resource.");
              }

              using (var sr = new StreamReader(readabilityStylesheetStream))
              {
            styleElement.SetInnerHtml(sr.ReadToEnd());
              }

              headElement.Add(styleElement);

              /* Apply reading style to body. */
              string readingStyleClass = GetReadingStyleClass(_readingStyle);

              documentBody.SetClass(readingStyleClass);
              documentBody.SetStyle("display: block;");
              documentBody.RemoveAll();

              if (articleTitleElement != null)
              {
            documentBody.Add(articleTitleElement);
              }

              if (articleContentElement != null)
              {
            documentBody.Add(articleContentElement);
              }
        }

using System;