C# selenium SocketException when calling ChromeDriver.Naviga

Question

我开始使用Selenium并不多。我正在编写一个 WPF 应用程序，该应用程序应该自动在此站点上查找书籍，然后在 ListView 上表示结果。起初一切都很好，当我决定第二次搜索时，问题就出现了。每次按下搜索按钮时，我都会调用 Navigate((。WebDriver 的 GoToUrl(( 方法，第一次之后，如果我再次按下它，我会得到这个：

OpenQA.Selenium.WebDriverException: 'Unexpected error. System.Net.WebException: Impossible to connect with the remote server. ---> System.Net.Sockets.SocketException: Impossible to estabilish a connection. Persistent refusal of the computer 127.0.0.1:52601
in System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
in System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception)
--- Fine della traccia dello stack dell'eccezione interna ---
in System.Net.HttpWebRequest.GetRequestStream(TransportContext& context)
in System.Net.HttpWebRequest.GetRequestStream()
in OpenQA.Selenium.Remote.HttpCommandExecutor.Execute(Command commandToExecute)
in OpenQA.Selenium.Remote.DriverServiceCommandExecutor.Execute(Command commandToExecute)

这是我的 MainWindow 类，一切都完成了：

MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows;
using System.Windows.Input;
using System.Xml;
using System.IO;
using System.Net;
using System.Windows.Controls;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using OpenQA.Selenium.Support.UI;
using System.Threading;
namespace MyLibrary
{
    /// <summary>
    /// Logica di interazione per MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        Catalog catalog;
        List<Category> categories;
        XmlDocument catalogXml;
        string xmlPath;
        ChromeDriver resultFinder;
        Thread resultFinderThread;
        string searchName;
        struct ResultViewListItem
        {
            public string N { get; set; }
            public string Result { get; set; }
        }
        public MainWindow()
        {
            InitializeComponent();
            LoadCatalog();
            LoadResultFinder();
        }
        private void LoadCatalog()
        {
            categories = new List<Category>();
            xmlPath = "C:/Users/Andrea Ferrando/Documents/Visual Studio 2017/Projects/Andrea/MyLibrary/MyLibrary/Catalog/catalog.xml";
            catalogXml = new XmlDocument();
            catalogXml.Load(xmlPath);
            foreach(XmlNode node in catalogXml.DocumentElement.ChildNodes)
            {
                categories = getCategories(categories, node);
            }
            catalog = new Catalog(categories, catalogXml, xmlPath);
        }
        private List<Category> getCategories(List<Category> categories, XmlNode node)
        {
            int number = Int32.Parse(node.Attributes["number"].Value);
            string description = node.Attributes["description"].Value;
            Category category = new Category(number, description, categories);
            categories.Add(category);
            if(node.HasChildNodes)
            {
                foreach (XmlNode child in node.ChildNodes)
                {
                     category.Children = getCategories(category.Children, child);
                }
                return categories;
            }
            return categories;
        }
        private void LoadResultFinder()
        {
            ChromeOptions chromeOptions = new ChromeOptions();
            chromeOptions.AddArgument("--window-position=-32000,-32000");
            ChromeDriverService chromeDriverService = ChromeDriverService.CreateDefaultService();
            chromeDriverService.HideCommandPromptWindow = true;
            resultFinder = new ChromeDriver(chromeDriverService, chromeOptions);
            searchName = "";
        }
        private void Grid_PreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            if(e.Source.Equals(FindName("Search")))
            {
                TextBox textBox = (TextBox)FindName("SearchBox");
                searchName = textBox.Text;
                resultFinderThread = new Thread(new ThreadStart(findResults));
                resultFinderThread.Start();
            }
        }
        private void findResults()
        {
            using (resultFinder)
            {
                resultFinder.Navigate().GoToUrl("http://www.sbn.it/opacsbn/opac/iccu/free.jsp");
                IWebElement inputField = resultFinder.FindElementByName("item:1016:Any");
                inputField.SendKeys(searchName);
                IWebElement submitField = resultFinder.FindElementByName("Invia");
                submitField.Click();
                IWebElement table = resultFinder.FindElementById("records");
                IList<IWebElement> trElements = table.FindElements(By.TagName("tr"));
                IList<IWebElement> tdElements;
                List<string> information = new List<string>();
                foreach (IWebElement trElement in trElements)
                {
                    tdElements = trElement.FindElements(By.TagName("td"));
                    information.Add(tdElements[2].Text);
                }
                Dispatcher.Invoke(() =>
                {
                    ListView listView = (ListView)FindName("ResultsList");
                    for (int i = 0; i < information.Count; i++)
                    {
                        listView.Items.Add(new ResultViewListItem { N = (i + 1).ToString(), Result = information[i] });
                    }
                });
            }
        }
    }
}

重要的方法是 FindResults((我希望我已经足够清楚了，提前谢谢。

Answer 1

我猜你的连接在你第二次调用它时以某种方式接近。

我想你也在调用拖曳时间的方法findResults().

问题是您使用的是 using 语句。此语句在退出代码块后释放连接。在此答案中，您可以找到有关其工作原理的更多信息。

在使用完对象之前，不应释放该对象。我会删除using开始，然后我会使用其他一些技术来释放对象。

希望这有帮助。