Question

我在C＃-Program中遇到了WebBrowsing自动化的问题。我之前使用过代码来获取BHO，并且它正在运行。但在纯粹的c＃程序中，似乎存在某种僵局。我已经指示我的程序点击搜索按钮，然后等待（通过手动重新发送）文档完成信号。但是现在似乎在ManualResetEvent发出超时信号之前不会处理点击搜索按钮。此后点击进行，同时触发DocumentComplete-Event。

对于该程序的结构： WebBrowser-Control是WindowsForm的一部分。 WebBrowser控件传递给运行Thread的Class。该类再次将控件传递给另一个类，其中根据加载的webbrowser编写具体行为。

所以在Code中这样看是这样的：

线程的设置

_runner = new Thread(runner);
_runner.SetApartmentState(ApartmentState.STA);
_runner.IsBackground = true;
_runner.Start();

使用Runner-Method处理
```
b.placeTipp(workStructure);
```

PlaceTipp-Method

public void placeTipp(ref OverallTippStructure tipp)
    {
        _expectedUrl = String.Empty;
        _betUrl = String.Empty;
        _status = BookieStatusType.CHECKLOGIN;

        while (true)
        {
            _mreWaitForAction.Reset();
            checkIETab();

            switch (_status)
            {
                case BookieStatusType.REQUESTWEBSITE:
                    ConsoleWriter.writeToConsole(String.Format("Bookie {0}: Keine IE-Tab vorhanden. Fordere eine an", this.BookieName));
                    //if (RequestIETabEvent != null)
                    //    RequestIETabEvent(this, new EventArgs());
                    _status = BookieStatusType.NAVIGATETOWEBSITE;
                    _mreWaitForAction.Set();
                    break;
                case BookieStatusType.NAVIGATETOWEBSITE:                                                
                    _webBrowser.Navigate(@"http://www.nordicbet.com");
                    break;
                case BookieStatusType.CHECKLOGIN:
                    checkLogin();
                    break;
                case BookieStatusType.LOGINNEEDED:
                    doLogin();
                    break;
                case BookieStatusType.LOGGEDIN:
                    _status = BookieStatusType.SEARCHTIPP;
                    _mreWaitForAction.Set();
                    break;
                case BookieStatusType.SEARCHTIPP:
                    searchTipp(tipp);
                    break;
                case BookieStatusType.NAVTOSB:
                    NavToSB();
                    break;
                case BookieStatusType.GETMARKET:
                    getMarket(tipp);
                    break;
                case BookieStatusType.PLACEBET:
                    placeBet(tipp);
                    break;
                case BookieStatusType.CONFIRMBET:
                    confirmBet();
                    break;
                case BookieStatusType.EXTRACTBETDATA:
                    extractBetId(ref tipp);
                    break;
                case BookieStatusType.FINISHED:
                    return;
            }


            if (!_mreWaitForAction.WaitOne(60000))
            {
                //Sonderüberpüfung be LoginNeeded
                if (_status == BookieStatusType.LOGINNEEDED)
                {
                    //checkLogin();
                    throw new BookieLoginFailedExcpetion();
                }
                //TIMEOUT!
                ConsoleWriter.writeToConsole(String.Format("Bookie {0}: Timeout bei warten auf nächsten Schritt. Status war {1}", this.BookieName, this._status.ToString()));
                throw new BookieTimeoutExcpetion(String.Format("Bookie {0}: Timeout bei dem Warten auf Ereignis", this.BookieName));
            }
        }
    }

发生死锁的SearchTipp-Method：

private void searchTipp(OverallTippStructure tipp)
    {
        if (_webBrowser.InvokeRequired)
        {
            _webBrowser.Invoke(new delegatePlaceBet(searchTipp), new object[] { tipp });
        }
        else
        {
            ConsoleWriter.writeToConsole(String.Format("Bookie {0}: Suche Tipp {1}", this.BookieName, tipp.BookieMatchName));
            _expectedUrl = String.Empty;
            if (!_webBrowser.Url.ToString().StartsWith("https://www.nordicbet.com/eng/sportsbook"))
            {
                ConsoleWriter.writeToConsole(String.Format("Bookie {0}: Nicht auf Sportsbookseite. Navigiere", this.BookieName));
                _status = BookieStatusType.NAVTOSB;
                _mreWaitForAction.Set();
                return;
            }
            _searchCompleted = false;
            HtmlDocument doc = _webBrowser.Document;

            if (doc != null)
            {

                mshtml.IHTMLInputElement elemSearch = (mshtml.IHTMLInputElement)doc.GetElementById("query").DomElement;
                if (elemSearch != null)
                {
                    Thread.Sleep(Delayer.delay(2000, 10000));
                    elemSearch.value = tipp.BookieMatchName;

                    mshtml.IHTMLElement elemSearchButton = (mshtml.IHTMLElement)doc.GetElementById("search_button").DomElement;
                    if (elemSearchButton != null)
                    {
                        Thread.Sleep(Delayer.delay(900, 4000));

                        elemSearchButton.click();
                        //elemSearchButton.InvokeMember("click");

                        if (!_mreWaitForAction.WaitOne(10000)) //Here The Deadlock happens
                        {
                            //Now the click event and therefor the search will be executed
                            ConsoleWriter.writeToConsole(String.Format("Bookie {0}: Suche ist auf Timeout gelaufen", this.BookieName));
                            throw new BookieTimeoutExcpetion(String.Format("Bookie {0}: Suche ist auf Timeout gelaufen", this.BookieName));
                        }                                                        

                        _mreWaitForAction.Reset();
                        HtmlElement spanResult = doc.GetElementById("total_ocs_count");
                        while (spanResult == null)
                        {
                            Thread.Sleep(500);
                            spanResult = doc.GetElementById("total_ocs_count");
                        }

                        int total_ocs_count = 0;
                        if (!Int32.TryParse(spanResult.InnerHtml, out total_ocs_count))
                        {
                            ConsoleWriter.writeToConsole(String.Format("Bookie {0}: Tip {1} nicht gefunden", this.BookieName, tipp.BookieMatchName));
                            throw new BookieTippNotFoundExcpetion(String.Format("Bookie {0}: Tip {1} nicht gefunden", this.BookieName, tipp.BookieMatchName));
                        }

                        if (total_ocs_count <= 0)
                        {
                            ConsoleWriter.writeToConsole(String.Format("Bookie {0}: Tip {1} nicht gefunden", this.BookieName, tipp.BookieMatchName));
                            throw new BookieTippNotFoundExcpetion(String.Format("Bookie {0}: Tip {1} nicht gefunden", this.BookieName, tipp.BookieMatchName));
                        }
                        /*
                    else if (total_ocs_count > 1)
                    {
                        throw new BookieMoreThanOneFoundExcpetion(String.Format("Bookie {0}: Tipp {1} nicht eindeutig", this.BookieName, tipp.BookieMatchName));
                    }
                    */
                        ConsoleWriter.writeToConsole(String.Format("Bookie {0}: Tip {1} gefunden", this.BookieName, tipp.BookieMatchName));
                        _status = BookieStatusType.GETMARKET;
                    }
                }
            }
            _mreWaitForAction.Set();
        }
    }

有人知道这里发生了什么吗？

由于

lichtbringer

Answer 1

通过执行_webBrowser.Invoke(new delegatePlaceBet(searchTipp), new object[] { tipp })，可以在主UI线程上同步执行searchTipp方法。这是可以理解的，因为您无法从创建控件的原始线程以外的任何线程访问WebBrowser API。

但是，通过这样做，{@ 1}}调用将在主UI线程上执行，从而有效地阻止了消息循环（由_mreWaitForAction.WaitOne(10000)启动）。 Application.Run需要一个功能性的消息循环，它会不断地传递Windows消息，否则WebBrowser不会被解雇，并且您将陷入僵局。

我的理解是，您只需在此处创建另一个线程来组织自动化方案的工作流程。 你真的不需要另一个线程。 Here's an example如何使用DocumentCompleted / async异步地在主UI线程上完成它，并且here's an example在控制台应用中使用await。

或者，作为解决方法，您可以使用here中的WebBrowser，如下所示：WaitWithDoEvents。它在等待处理消息时等待处理。您应该了解potential implications使用_mreWaitForAction.WaitWithDoEvents(10000)创建嵌套消息循环。

注意，如果使用嵌套的消息循环，则仍然不需要单独的线程。它将为您提供主UI线程上的线性代码工作流程。例如：

Application.DoEvents()

虽然如上所述，你可以使用private void buttonStart_Click(object sender, EventArgs e) { using (var mre = new ManualResetEvent(false)) { WebBrowserDocumentCompletedEventHandler handler = (s, args) => mre.Set(); this.webBrowser.DocumentCompleted += handler; try { this.webBrowser.Navigate("http://www.example.com"); mre.WaitWithDoEvents(10000); } finally { this.webBrowser.DocumentCompleted -= handler; } } MessageBox.Show(this.webBrowser.Document.Body.OuterHtml); } / async更自然地实现同样的目的，而不使用嵌套的消息循环，这是执行此操作的首选方式，IMO。

EventHandle.WaitOne + WebBrowser =等待DocumentComplete时出现死锁

1 个答案: