Batch Printing in C#

Question

I am currently working on an application which creates many WPF controls, batches them and then sends them to a printer.

The problem I am having is that the application waits for the previous batch to finish before creating the next batch. This means that the printer is then waiting for the second batch rather than it being ready when it finishes printing the first batch.

Is there any way I can send a fixed document to print async??

Here is what I have so far...

void PrintInBatch(IList<object> objsToPrint, int batchSize)
{
     int printed = 0;
     while (printed < objsToPrint.Count())
     { 
         IList<object> batchToPrint = objsToPrint.Skip(printed).Take(batchSize);

         this.Print(batchToPrint);

         printed += batchSize;
     }
}

void  Print(IList<object> objsToPrint)
{
    const double width = 5.8*96;
    const double height = 8.3*96;

    var pageSize = new Size(width, height); // A5 page, at 96 dpi
    var document = new FixedDocument();
    document.DocumentPaginator.PageSize = pageSize;

    int iii = 0;
    //Add packslips to document
    foreach (object objToPrint in objsToPrint)
    {
        PrintControl printControl = new PrintControl();
        printControl.SetDetails(objToPrint);

        var fixedPage = new FixedPage();
        fixedPage.Width = pageSize.Width;
        fixedPage.Height = pageSize.Height;

        fixedPage.Children.Add(printControl);
        fixedPage.Measure(pageSize);
        fixedPage.Arrange(new Rect(new Point(), pageSize));
        fixedPage.UpdateLayout();

        var pageContent = new PageContent();
        ((IAddChild) pageContent).AddChild(fixedPage);
        document.Pages.Add(pageContent);
     }

     PrintQueue queue = new LocalPrintServer().GetPrintQueue(printerName);
     dlg.PrintQueue = queue;

     PageMediaSize pageMedia = new PageMediaSize(PageMediaSizeName.ISOA5);
     dlg.PrintTicket.PageMediaSize = pageMedia;
     dlg.PrintTicket.Duplexing = Duplexing.OneSided;
     dlg.PrintDocument(document.DocumentPaginator, "Packslips"); //Program waits here until print finished
 }

I have tried running dlg.PrintDocument() method on a separate thread but this causes an error.

Any ideas??

Thanks

UPDATE

I have tried threading the PrintInBatch(); and this does work however it means that every batch is created at the same time, which is a massive resource drain.

I did it like this:

void PrintInBatch(IList<object> objsToPrint, int batchSize)
{
     int printed = 0;
     while (printed < objsToPrint.Count())
     { 
         IList<object> batchToPrint = objsToPrint.Skip(printed).Take(batchSize);

         Thread thread = new Thread(() => this.Print(batchToPrint));
         thread.SetApartmentState(ApartmentState.STA);
         thread.Start();

         printed += batchSize;
     }
}

score 0 · Answer 1 · edited May 23 '17 at 12:21

You can't run the PrintDocument method off thread because it requires UI objects on the STA thread to run. You can try the option here (render the document off thread, then print on the main thread) Printing the content of a DocumentViewer in a different UI thread

There is also a possible way of implementing print dialog on a background thread. Try this link (its certainly not easy):

http://www.infragistics.com/community/forums/p/71258/360560.aspx

Also, consider batching or rendering the documents in memory beforehand. Its easier to do that off thread and gets the performance up a lot.

Batch Printing in C#

1 Answers1