Can't Print Specific Word Document Using VB.Net [duplicate] - vb.net

Question

I have a C# WinForm application that opens and fills out a MS Word dotx template by placing text at bookmarks, and then attempts to print it, all using MS Word Interop 15.
Everything seems to go fine, the print dialog shows and completes OK, the print job shows up in the print queue (i.e. the "See what's printing" window from "Devices and Printers" on MS Windows 10). But then the job immediately disappears from the queue before it can be spooled! (document appears very very briefly with "Spooling" status, and does not print - the printer never gets the job)
Here is my code (exception checking removed for brevity):
using Word = Microsoft.Office.Interop.Word;
private void Print_Click(object sender, EventArgs e)
{
// Open the MS Word application via Office Interop
Word.Application wordApp = new Word.Application();
Word.Document wordDoc;
// Open the template
wordDoc = wordApp.Documents.Add(Template: ContractTemplatePath, Visible: false);
// Ensure the opened document is the currently active one
wordDoc.Activate();
// Set the text for each bookmark from the corresponding data in the GUI
SetBookmarkText(wordDoc, "Foo", fooTextBox.Text);
// ... There's a whole bunch of these ... then:
// Instantiate and configure the PrintDialog
var pd = new PrintDialog()
{
UseEXDialog = true,
AllowSomePages = false,
AllowSelection = false,
AllowCurrentPage = false,
AllowPrintToFile = false
};
// Check the response from the PrintDialog
if (pd.ShowDialog(this) == DialogResult.OK)
{
// Print the document
wordApp.ActivePrinter = pd.PrinterSettings.PrinterName;
wordDoc.PrintOut(Copies: pd.PrinterSettings.Copies);
}
// Close the document without saving the changes (once the
// document is printed we don't need it anymore). Then close
// the MS Word application.
wordDoc.Close(SaveChanges: false);
wordApp.Quit(SaveChanges: false);
}
The only thing I can think of here is that maybe because I do away with the document as soon as I've sent it to the printer, then the job hasn't been completely sent so it removes itself or something. If this is the case then how can I determine how long I need to keep the document around for and what's the best way of waiting for that?
EDIT: Ive done another small bit of research (dont have time for more on this just at this moment) that suggests I may be able to use the PrintEnd event, but I couldn't immediately see if this would be applicable when using Interop. Would it be a method of achieving what I want without polling?

Answer 1

One solution is to poll the BackgroundPrintingStatus property of the Word application. It holds a count of the documents still waiting in the printing queue. While this count is greater than 0 there are still documents awaiting printing.
There are many ways you could achieve this. Here's a simple loop which blocks the UI:
// Send document to printing queue here...
while (wordApp.BackgroundPrintingStatus > 0)
{
// Thread.Sleep(500);
}
// Printing finished, continue with logic
Alternatively you may want to wrap it in a task so that you can do other things while waiting:
await Task.Run(async () => { while (wordApp.BackgroundPrintingStatus > 0)
{ await Task.Delay(500); } });