Visual Studio文本Visualizer中的错误

Question

我有以下课程：

internal static class WebRequester
{
    /// <summary>
    /// Sending GET request.
    /// </summary>
    /// <param name="url">Request Url.</param>
    /// <param name="data">Data for request.</param>
    /// <param name="userName">user name for log in</param>
    /// <param name="password">password for log in</param>
    /// <returns>Response body.</returns>
    public static string HttpGet(string url, string data, string userName, string password, string contentType = "application/json")
    {
        string Out = String.Empty;
        Uri uri = new Uri(url);
        CookieContainer cookieContainer = new CookieContainer();

        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url + (string.IsNullOrEmpty(data) ? "" : "?" + data));
        req.ContentType = contentType;
        req.Method = "GET";
        req.Accept = "Accept: text/html,application/xhtml+xml,application/xml";
        req.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.106 Safari/537.36";
        req.KeepAlive = true;
        req.CookieContainer = cookieContainer;

        AddAuthentication(userName, password, req);
        try
        {
            System.Net.WebResponse resp = req.GetResponse();
            using (System.IO.Stream stream = resp.GetResponseStream())
            {
                using (System.IO.StreamReader sr = new System.IO.StreamReader(stream))
                {
                    Out = sr.ReadToEnd();
                    sr.Close();
                }
            }
        }
        catch (ArgumentException ex)
        {
            Out = string.Format("HTTP_ERROR :: The second HttpWebRequest object has raised an Argument Exception as 'Connection' Property is set to 'Close' :: {0}", ex.Message);
        }
        catch (WebException ex)
        {
            Out = string.Format("HTTP_ERROR :: WebException raised! :: {0}", ex.Message);
        }
        catch (Exception ex)
        {
            Out = string.Format("HTTP_ERROR :: Exception raised! :: {0}", ex.Message);
        }

        return Out;
    }

    private static void AddAuthentication(string userName, string password, HttpWebRequest req)
    {
        if (!string.IsNullOrEmpty(userName) && !string.IsNullOrEmpty(password))
        {
            string base64Credentials = GetEncodedCredentials(userName, password);
            req.Headers.Add("Authorization", "Basic " + base64Credentials);
        }
    }


    private static string GetEncodedCredentials(string userName, string password)
    {
        string mergedCredentials = string.Format("{0}:{1}", userName, password);
        byte[] byteCredentials = UTF8Encoding.UTF8.GetBytes(mergedCredentials);
        return Convert.ToBase64String(byteCredentials);
    }
}

和另一个班级：

public class ErrorVisualizer
{
    private const string contentType = "text/html; charset=UTF-8";
    public void ShowErrorInVisualizer()
    {
        string url = "https://www.tenderned.nl/tenderned-web/aankondiging/overzicht/aankondigingenplatform";
        string resultsStart = "<ol class=\"results announcements\">";
        var pageContent = WebRequester.HttpGet(url, "", "", "", contentType);
        var idxResultsStart = pageContent.IndexOf(resultsStart);
    }
}

按钮点击事件跟随操作：

var ev = new ErrorVisualizer();
ev.ShowErrorInVisualizer();

然后在mehtod的调试过​​程中，ShowErrorInVisualizer（）idxResultsStart总是大于零，所以这意味着在pageContent中有一个字符串

但是如果要通过文本可视化工具复制pageContent变量，

并将该内容粘贴到记事本中，我将无法在记事本中找到字符串。

所以，我的问题是如何才能看到变量pageContent的真正含义？