標籤中的C＃HTML標籤

Question

我有點鹹菜。有一張我想在網站上抓取的圖像列表。我知道如何做到這一點，但我必須過濾出圖像的位置。

如我想要抓住一個ID爲「theseImages」的div標籤中的圖像，但另一個div標籤中有另一組圖像，其ID爲「notTheseImages」。將每個標籤循環到具有標籤「img」的HtmlElementCollection中，將忽略div，因爲它也會從「notTheseImages」中獲取圖像。

有沒有一種方法可以循環顯示圖像，同時檢查這些圖像在div標籤中的位置？

Answer 1

這可以幫助你做你的當前HTML的選擇，也許對未來occassions :)

protected HtmlElement[] GetElementsByParent(HtmlDocument document, HtmlElement baseElement = null, params string[] singleSelectors) 
{ 
    if (singleSelectors == null || singleSelectors.Length == 0) 
    { 
     throw new Exception("Please give at least 1 selector!"); 
    } 
    IList<HtmlElement> result = new List<HtmlElement>(); 
    bool last = singleSelectors.Length == 1; 
    string singleSelector = singleSelectors[0]; 
    if (string.IsNullOrWhiteSpace(singleSelector) || string.IsNullOrWhiteSpace(singleSelector.Trim())) 
    { 
     return null; 
    } 
    singleSelector = singleSelector.Trim(); 
    if (singleSelector.StartsWith("#")) 
    { 
     var item = document.GetElementById(singleSelector.Substring(1)); 
     if (item == null) 
     { 
      return null; 
     } 
     if (last) 
     { 
      result.Add(item); 
     } 
     else 
     { 
      var results = GetElementsByParent(document, item, singleSelectors.Skip(1).ToArray()); 
      if (results != null && results.Length > 0) 
      { 
       foreach (var res in results) 
       { 
        result.Add(res); 
       } 
      } 
     } 
    } 
    else if (singleSelector.StartsWith(".")) 
    { 
     if (baseElement == null) 
     { 
      baseElement = document.Body; 
     } 
     foreach (HtmlElement child in baseElement.Children) 
     { 
      string cls; 
      if (!string.IsNullOrWhiteSpace((cls = child.GetAttribute("class")))) 
      { 
       if (cls.Split(' ').Contains(singleSelector.Substring(1))) 
       { 
        if (last) 
        { 
         result.Add(child); 
        } 
        else 
        { 
         var results = GetElementsByParent(document, child, singleSelectors.Skip(1).ToArray()); 
         if (results != null && results.Length > 0) 
         { 
          foreach (var res in results) 
          { 
           result.Add(res); 
          } 
         } 
        } 
       } 
      } 
     } 
    } 
    else 
    { 
     HtmlElementCollection elements = null; 

     if (baseElement != null) 
     { 
      elements = baseElement.GetElementsByTagName(singleSelector); 
     } 
     else 
     { 
      elements = document.GetElementsByTagName(singleSelector); 
     } 
     foreach (HtmlElement item in elements) 
     { 
      if (last) 
      { 
       result.Add(item); 
      } 
      else 
      { 
       var results = GetElementsByParent(document, item, singleSelectors.Skip(1).ToArray()); 
       if (results != null && results.Length > 0) 
       { 
        foreach (var res in results) 
        { 
         result.Add(res); 
        } 
       } 
      } 
     } 
    } 
    return result.ToArray(); 
} 

private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e) 
{ 
    // here we can query 
    var result = GetElementsByParent(webBrowser1.Document, null, "#theseImages", "img"); 
} 

結果，那麼可能會包含在#theseImages

心靈你GetElementsByParent是圖像相當未經測試，我只是測試它的用例，它似乎是好的。

不要忘記，一旦你確認文檔完成只是開始查詢;）