多线程挂起UI？

Posted 2023-04-12

【中文标题】多线程挂起UI？

【英文标题】：Multi threading hangs UI?

【发布时间】：2019-07-08 09:28:19

【问题描述】：

我正在使用多线程来使任务更快更流畅，当结果增加到 Richtextbox 时 UI 开始挂起，不知道为什么，我在线程中创建了一个 webbrowser，并在单线程中做一些其他的事情！

使用线程作为 STA（单线程类型）

这是代码的 sn-p ！

  foreach (string line in URLLMemoRichTxt.Lines)
                
                    string href = line;
                    if (href.Trim() != string.Empty)
                    
                        //XtraMessageBox.Show(href);
                        if (StopGettingInnerLink == true)
                        
                            AddLog("Getting links has been stopped successfully!");
                            StopGettingInnerLink = true;
                            break;
                        
                        else if (StopGettingInnerLink == false)
                        
                            AddLog("Getting links from " + href);
                            runBrowserThread( new Uri(href));
                            await Task.Delay(5000);
                            AddLog("Giving the tool some rest for 5 seconds ! ");
                        
                    
                


     private void runBrowserThread(Uri url)
        
             browserth = new Thread(() => 
                var br = new WebBrowser();
                br.ScriptErrorsSuppressed = true;
                br.DocumentCompleted += browser_DocumentCompleted;
                br.Navigate(url);
                Application.Run();
            );
            browserth.SetApartmentState(ApartmentState.STA);
            browserth.Start();

        

      void browser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        
            var br = sender as WebBrowser;
            string currentURL = br.Url.ToString();
            if (br.Url == e.Url)
            


                htmlElementCollection acollection = br.Document.GetElementsByTagName("a");
                foreach (HtmlElement a in acollection)
                

                    string href = a.GetAttribute("href");

                    if (URLLMemoRichTxt.InvokeRequired)
                    
                        URLLMemoRichTxt.Invoke((MethodInvoker)delegate ()
                        
                            if (!URLList.Contains(href) && href.Trim() != string.Empty && !href.Contains(".jpg") && !href.Contains(".png") && !href.Contains(".gif") && !href.Contains(".jpeg"))
                            
                                URLList.Add(href);
                                // URLListView.Items.Add(href);
                                // adding new link ino listview ! 
                                //   URLListCountLBL.Text = URLListView.Items.Count.ToString();
                                URLLMemoRichTxt.Text += href + "\n";

                                URLListCountLBL.Text = URLLMemoRichTxt.Lines.Length.ToString();
                                //   runbrowserinthread(href);

                            
                        );

                    
                    else
                    
                        if (!URLList.Contains(href) && href.Trim() != string.Empty && !href.Contains(".jpg") && !href.Contains(".png") && !href.Contains(".gif") && !href.Contains(".jpeg"))
                        
                            URLList.Add(href);
                            //                                                      URLListView.Items.Add(href);
                            URLLMemoRichTxt.Text += href + "\n";

                            URLListCountLBL.Text = URLLMemoRichTxt.Lines.Length.ToString();
                            //     GetInnerLink(href);
                        
                    

                

                AddLog("All  links has been scrapped successfully for \r\n" + currentURL);

                Application.ExitThread();   // Stops the thread
            
        

【参考方案1】：

自己已经找到了解决方案：

替换：

                    URLLMemoRichTxt.Text += href + "\n";

与：

  URLLMemoRichTxt.AppendText(Environment.NewLine + href);