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等待網頁完成加載的C#代碼

[英]C# code to wait until webpage finishes loading

我一輩子都想不通如何讓我的C#代碼等到網頁完成加載。 我什至無法接近ie.documentcompleted或ie.documentcomplete。 實際上,即使我引用的是system.windows.forms程序集,我也無法使用VS2012作為下拉選項為我提供documentcomplete。 請幫忙。

謝謝

public static string getTheBlockArray()
        {
            SHDocVw.InternetExplorer IE = new SHDocVw.InternetExplorer();
            string id = "resultsTable";
            object Empty = 0;
            object URL = "http://www.cmegroup.com/clearing/trading-practices/block-data.html#contractTypes=FUT,OPT,SPD&exchanges=XCME&assetclass=assetClassId=1,6";
            IE.Navigate2(ref URL, ref Empty, ref Empty, ref Empty, ref Empty);

            // Some code here to wait until the webpage loads

            object theRange = IE.Document.getelementbyID(id).innertext;
            string blockString = theRange.ToString();
            IE.Quit();
            return blockString;
        }

嘗試這個:

while(IE.Busy)
{
    //You might want to sleep or count or something.
    //System.Threading.Thread.Sleep(1000);
}

IE.Completed無法正常工作嗎?

如果可以,您可以嘗試執行以下操作:

IE.completed += (s, e) => {
  // your code

};

javascript代碼通過異步請求填充的resultTable元素的內容。 因此,您不應該處理DOM,而必須像javascript一樣直接查詢數據。 下面的代碼可能是一個很好的起點。

  class Program
  {
    private static readonly string url = "http://www.cmegroup.com/clearing/trading-practices/CmeWS/mvc/xsltTransformer.do?xlstDoc=/XSLT/md/blocks-records.xsl&url=/da/BlockTradeQuotes/V1/Block/BlockTrades?exchange={0}&foi={1}&{2}&tradeDate={3}&sortCol={4}&sortBy={5}&_=1372913232800";

    static void Main(string[] args)
    {
      Exchange exchange = Exchange.XCME;
      ContractType contractType = ContractType.FUT | ContractType.OPT | ContractType.SPD;
      string assetClass = "assetClassId=0"; // See asset_class dropdown options in HTML source for valid values
      DateTime tradeDate = new DateTime(2013, 7, 3);
      string sortCol = "time"; // Column to sort
      SortOrder sortOrder = SortOrder.desc;

      string xml = QueryData(exchange, contractType, assetClass, tradeDate, sortCol, sortOrder);
      Console.WriteLine(xml);
    }

    private static string QueryData(Exchange exchange, ContractType contractType, string assetClass, DateTime tradeDate, string sortCol, SortOrder sortOrder)
    {
      string exc = GetEnumString(exchange);
      string ct = GetEnumString(contractType);
      string td = tradeDate.ToString("MMddyyyy");
      string query = string.Format(url, exc, ct, assetClass, td, sortCol, sortOrder.ToString());

      WebRequest request = WebRequest.Create(query);
      request.Credentials = CredentialCache.DefaultCredentials;
      using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
      {
        using (Stream stream = response.GetResponseStream())
        {
          using (StreamReader reader = new StreamReader(stream))
          {
            return reader.ReadToEnd();
          }
        }
      }
    }

    private static string GetEnumString(Enum item)
    {
      return item.ToString().Replace(" ", "");
    }
  }

  [Flags]
  enum Exchange
  {
    /// <summary>
    /// CBOT.
    /// </summary>
    XCBT = 1,

    /// <summary>
    /// CME.
    /// </summary>
    XCME = 2,

    /// <summary>
    /// COMEX.
    /// </summary>
    XCEC = 4,

    /// <summary>
    /// DME.
    /// </summary>
    DUMX = 8,

    /// <summary>
    /// NYMEX.
    /// </summary>
    XNYM = 16
  }

  [Flags]
  enum ContractType
  {
    /// <summary>
    /// Futures.
    /// </summary>
    FUT = 1,

    /// <summary>
    /// Options.
    /// </summary>
    OPT = 2,

    /// <summary>
    /// Spreads.
    /// </summary>
    SPD = 4
  }

  enum SortOrder
  {
    /// <summary>
    /// Ascending.
    /// </summary>
    asc,

    /// <summary>
    /// Descending.
    /// </summary>
    desc
  }

結果在xml變量中( 請參閱參考資料)。

祝好運。

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