c# - 使用线程 C# 时 UI 挂起

Question

我正在使用多线程来执行一些任务，但是当我启动进程时，UI 挂起，我在另一个解决方案中使用相同的方法并且它工作正常!

这是一个片段。我也尝试使用 HTMLagality，但我不认为这是原因，此方法使用普通的 http 网络请求

使用 C#、VS 2015、.Net Framework 4.6.1

 var th = new Thread(() =>
            {
                if (LinksToGetEmailsListView.InvokeRequired)
                {
                    LinksToGetEmailsListView.Invoke((MethodInvoker)delegate ()
                    {
                        foreach (ListViewItem link in LinksToGetEmailsListView.Items)
                        {       
                            #region Extracting Emails from Html Page
                            //instantiate with this pattern 

                            HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(link.Text);
                            httpWebRequest.UseDefaultCredentials = true;
                            httpWebRequest.UserAgent = @"Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Trident/6.0)";

                            httpWebRequest.Method = WebRequestMethods.Http.Get;
                            httpWebRequest.Accept = "application/json; charset=utf-8";

                            string file;
                            var response = (HttpWebResponse)httpWebRequest.GetResponse();
                            using (var sr = new StreamReader(response.GetResponseStream()))
                            {
                                file = sr.ReadToEnd();
                            }


                            string[] result = GetEmailsFromWebContent(file);
                            foreach (string r in result)
                            {
                                XtraMessageBox.Show(r);
                            }
                            #endregion






                            //   string[] result = GetEmailsFromWebContent(iWeb.Load(link.Text).DocumentNode.OuterHtml);
                            link.Focused = true;
                           // foreach (string email in result)
                            //{
                 //               XtraMessageBox.Show(email);
                            //}

                        }
                    });
                }
                else
                {
                    foreach (ListViewItem link in LinksToGetEmailsListView.Items)
                    {

                        #region Extracting Emails from Html Page
                        //instantiate with this pattern 

                        HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(link.Text);
                        httpWebRequest.UseDefaultCredentials = true;
                        httpWebRequest.UserAgent = @"Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Trident/6.0)";

                        httpWebRequest.Method = WebRequestMethods.Http.Get;
                        httpWebRequest.Accept = "application/json; charset=utf-8";

                        string file;
                        var response = (HttpWebResponse)httpWebRequest.GetResponse();
                        using (var sr = new StreamReader(response.GetResponseStream()))
                        {
                            file = sr.ReadToEnd();
                        }


                        string[] result = GetEmailsFromWebContent(file);
                        foreach (string r in result)
                        {
                            XtraMessageBox.Show(r);
                        }
                        #endregion
                    }

                }


            });
            th.SetApartmentState(ApartmentState.STA);
            th.Start();

Answer 1

您实际上是在 UI 线程上运行所有代码，这就是 UI 挂起的原因。你启动了一个辅助线程，但随后你立即做了一个InvokeRequired/Invoke查看。出色地;它将是必需的，因为您在辅助线程上。所以...您在辅助线程中做的第一件事就是将工作推回到 UI 线程。

您可能想推迟 Invoke直到您真正准备好更新 UI，即在最后一个 XtraMessageBox.Show 前后(可能还有周围的 foreach)。重要的是:将其从方法的前面移除。