c# - net - printdocument visual studio

Imprimir documento html desde el servicio de Windows en C#sin diálogo de impresión

Question

Estoy usando un servicio de Windows y quiero imprimir una página .html cuando comience el servicio. Estoy usando este código y está imprimiendo bien. Pero aparece un cuadro de diálogo de impresión, ¿cómo puedo imprimir sin el cuadro de diálogo Imprimir?

public void printdoc(string document)
{
    Process printjob = new Process();
    printjob.StartInfo.FileName = document;
    printjob.StartInfo.UseShellExecute = true;
    printjob.StartInfo.Verb = "print";
    printjob.StartInfo.CreateNoWindow = true;
    printjob.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;

    printjob.Start();
}

¿Hay alguna otra forma de imprimir esto sin mostrar el cuadro de diálogo de impresión?

Gracias de antemano, Anup Pal

Answer 1

En el servicio de Windows, el control del navegador web de Microsoft no funciona. Había usado ese código, funciona bien en la aplicación de Windows, pero cuando lo uso dentro de un servicio de Windows, el programa se queda atascado en esta línea.

axWebBrowser1.Navigate (@ "C: / mydoc.html", ref empty, ref empty, ref empty, ref empty);

gracias por responder, Anup Pal

Answer 2

Aquí está el Santo Grial.

Aprovechando StaTaskScheduler (tomado de Parallel Extension Extras ( lanzamiento en la Galería de códigos )).

Características: espera la finalización de la impresión, no muestra la configuración de impresión, con suerte es confiable.

Limitaciones: requiere C # 4.0, usa impresora predeterminada, no permite cambiar la plantilla de impresión

    TaskScheduler Sta = new StaTaskScheduler(1);
    public void PrintHtml(string htmlPath)
    {
        Task.Factory.StartNew(() => PrintOnStaThread(htmlPath), CancellationToken.None, TaskCreationOptions.None, Sta).Wait();
    }

    void PrintOnStaThread(string htmlPath)
    {
        const short PRINT_WAITFORCOMPLETION = 2;
        const int OLECMDID_PRINT = 6;
        const int OLECMDEXECOPT_DONTPROMPTUSER = 2;
        using(var browser = new WebBrowser())
        {
            browser.Navigate(htmlPath);
            while(browser.ReadyState != WebBrowserReadyState.Complete)
                Application.DoEvents();

            dynamic ie = browser.ActiveXInstance;
            ie.ExecWB(OLECMDID_PRINT, OLECMDEXECOPT_DONTPROMPTUSER, PRINT_WAITFORCOMPLETION);
        }
    }

//--------------------------------------------------------------------------
// 
//  Copyright (c) Microsoft Corporation.  All rights reserved. 
// 
//  File: StaTaskScheduler.cs
//
//--------------------------------------------------------------------------

using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;

namespace System.Threading.Tasks.Schedulers
{
    /// <summary>Provides a scheduler that uses STA threads.</summary>
    public sealed class StaTaskScheduler : TaskScheduler, IDisposable
    {
        /// <summary>Stores the queued tasks to be executed by our pool of STA threads.</summary>
        private BlockingCollection<Task> _tasks;
        /// <summary>The STA threads used by the scheduler.</summary>
        private readonly List<Thread> _threads;

        /// <summary>Initializes a new instance of the StaTaskScheduler class with the specified concurrency level.</summary>
        /// <param name="numberOfThreads">The number of threads that should be created and used by this scheduler.</param>
        public StaTaskScheduler(int numberOfThreads)
        {
            // Validate arguments
            if (numberOfThreads < 1) throw new ArgumentOutOfRangeException("concurrencyLevel");

            // Initialize the tasks collection
            _tasks = new BlockingCollection<Task>();

            // Create the threads to be used by this scheduler
            _threads = Enumerable.Range(0, numberOfThreads).Select(i =>
            {
                var thread = new Thread(() =>
                {
                    // Continually get the next task and try to execute it.
                    // This will continue until the scheduler is disposed and no more tasks remain.
                    foreach (var t in _tasks.GetConsumingEnumerable())
                    {
                        TryExecuteTask(t);
                    }
                });
                thread.IsBackground = true;
                thread.SetApartmentState(ApartmentState.STA);
                return thread;
            }).ToList();

            // Start all of the threads
            _threads.ForEach(t => t.Start());
        }

        /// <summary>Queues a Task to be executed by this scheduler.</summary>
        /// <param name="task">The task to be executed.</param>
        protected override void QueueTask(Task task)
        {
            // Push it into the blocking collection of tasks
            _tasks.Add(task);
        }

        /// <summary>Provides a list of the scheduled tasks for the debugger to consume.</summary>
        /// <returns>An enumerable of all tasks currently scheduled.</returns>
        protected override IEnumerable<Task> GetScheduledTasks()
        {
            // Serialize the contents of the blocking collection of tasks for the debugger
            return _tasks.ToArray();
        }

        /// <summary>Determines whether a Task may be inlined.</summary>
        /// <param name="task">The task to be executed.</param>
        /// <param name="taskWasPreviouslyQueued">Whether the task was previously queued.</param>
        /// <returns>true if the task was successfully inlined; otherwise, false.</returns>
        protected override bool TryExecuteTaskInline(Task task, bool taskWasPreviouslyQueued)
        {
            // Try to inline if the current thread is STA
            return
                Thread.CurrentThread.GetApartmentState() == ApartmentState.STA &&
                TryExecuteTask(task);
        }

        /// <summary>Gets the maximum concurrency level supported by this scheduler.</summary>
        public override int MaximumConcurrencyLevel
        {
            get { return _threads.Count; }
        }

        /// <summary>
        /// Cleans up the scheduler by indicating that no more tasks will be queued.
        /// This method blocks until all threads successfully shutdown.
        /// </summary>
        public void Dispose()
        {
            if (_tasks != null)
            {
                // Indicate that no new tasks will be coming in
                _tasks.CompleteAdding();

                // Wait for all threads to finish processing tasks
                foreach (var thread in _threads) thread.Join();

                // Cleanup
                _tasks.Dispose();
                _tasks = null;
            }
        }
    }
}

Answer 3

Para agregar a la limitación de Vadim, puede configurar la impresora predeterminada antes de imprimir utilizando:

    static void SetAsDefaultPrinter(string printerDevice)
    {
        foreach (var printer in PrinterSettings.InstalledPrinters)
        {
            //verify that the printer exists here
        }
        var path = "win32_printer.DeviceId=''" + printerDevice + "''";
        using (var printer = new ManagementObject(path))
        {
            printer.InvokeMethod("SetDefaultPrinter",
                                 null, null);
        }

        return;
    }

Y cambiando ligeramente el método PrintHtml con:

    public void PrintHtml(string htmlPath, string printerDevice)
    {
        if (!string.IsNullOrEmpty(printerDevice))
            SetAsDefaultPrinter(printerDevice);


        Task.Factory.StartNew(() => PrintOnStaThread(htmlPath), CancellationToken.None, TaskCreationOptions.None, _sta).Wait();
    }

Ahora no sé cómo será justo en un entorno de impresión pesado, ya que podría haber problemas de concurrencia al cambiar mucho la impresora predeterminada. Pero hasta ahora esto es lo mejor que se me ocurrió para arreglar esta limitación.