我有一个示例控制台应用程序，该应用程序使用WinForms打印一组HTML文件
WebBrowser。您
DoWorkAsync实际上可以在WinForms应用程序中借用它的一部分来完成打印任务，而无需进行任何更改：
// by Noseratio - http://stackoverflow.com/users/1768303/noseratiousing System;using System.Threading;using System.Threading.Tasks;using System.Windows.Forms;namespace ConsoleApplicationWebBrowser{ class Program { // Entry Point of the console app static void Main(string[] args) { try { // download each page and dump the content var task = MessageLoopWorker.Run(DoWorkAsync, "http://www.example.com", "http://www.example.net", "http://www.example.org"); task.Wait(); Console.WriteLine("DoWorkAsync completed."); } catch (Exception ex) { Console.WriteLine("DoWorkAsync failed: " + ex.Message); } Console.WriteLine("Press Enter to exit."); Console.ReadLine(); } // navigate WebBrowser to the list of urls in a loop static async Task<object> DoWorkAsync(object[] args) { Console.WriteLine("Start working."); var wb = new WebBrowser(); wb.scriptErrorsSuppressed = true; if (wb.document == null && wb.ActiveXInstance == null) throw new ApplicationException("Unable to initialize the underlying WebBrowserActiveX"); // get the underlying WebBrowser ActiveX object; // this pre depends on SHDocVw.dll COM interop assembly, // generate SHDocVw.dll: "tlbimp.exe ieframe.dll", // and add as a reference to the project var wbax = (SHDocVw.WebBrowser)wb.ActiveXInstance; TaskCompletionSource<bool> loadedTcs = null; WebBrowserdocumentCompletedEventHandler documentCompletedHandler = (s, e) => loadedTcs.TrySetResult(true); // turn event into awaitable task TaskCompletionSource<bool> printedTcs = null; SHDocVw.DWebBrowserEvents2_PrintTemplateTeardownEventHandler printTemplateTeardownHandler = (p) => printedTcs.TrySetResult(true); // turn event into awaitable task // navigate to each URL in the list foreach (var url in args) { loadedTcs = new TaskCompletionSource<bool>(); wb.documentCompleted += documentCompletedHandler; try { wb.Navigate(url.ToString()); // await for documentCompleted await loadedTcs.Task; } finally { wb.documentCompleted -= documentCompletedHandler; } // the DOM is ready, Console.WriteLine(url.ToString()); Console.WriteLine(wb.document.Body.OuterHtml); // print the document printedTcs = new TaskCompletionSource<bool>(); wbax.PrintTemplateTeardown += printTemplateTeardownHandler; try { wb.Print(); // await for PrintTemplateTeardown - the end of printing await printedTcs.Task; } finally { wbax.PrintTemplateTeardown -= printTemplateTeardownHandler; } Console.WriteLine(url.ToString() + " printed."); } wb.Dispose(); Console.WriteLine("End working."); return null; } } // a helper class to start the message loop and execute an asynchronous task public static class MessageLoopWorker { public static async Task<object> Run(Func<object[], Task<object>> worker, params object[] args) { var tcs = new TaskCompletionSource<object>(); var thread = new Thread(() => { EventHandler idleHandler = null; idleHandler = async (s, e) => { // handle Application.Idle just once Application.Idle -= idleHandler; // return to the message loop await Task.Yield(); // and continue asynchronously // propogate the result or exception try { var result = await worker(args); tcs.SetResult(result); } catch (Exception ex) { tcs.SetException(ex); } // signal to exit the message loop // Application.Run will exit at this point Application.ExitThread(); }; // handle Application.Idle just once // to make sure we're inside the message loop // and SynchronizationContext has been correctly installed Application.Idle += idleHandler; Application.Run(); }); // set STA model for the new thread thread.SetApartmentState(ApartmentState.STA); // start the thread and await for the task thread.Start(); try { return await tcs.Task; } finally { thread.Join(); } } }}
