Question

I am doing a bit of Office Automation and when printing a .doc file using VB.NET Office reference DLLs it causes great CPU load so I want to limit those processes to only use a single virtual core.

I haven’t been able to find anything in Microsoft’s documentation about this and I thought I would ask here as everyone is always so helpful.

This is the code I am using to print

   Dim oWordApp As Word.Application
   Dim oTargetDoc As Word.Document
   oWordApp = New Word.Application

   Select Case SQLdr("Priority")
          Case 1
                 oWordApp.WordBasic.FilePrintSetup(Printer:=printPriority1, DoNotSetAsSysDefault:=1)
          Case 2
                 oWordApp.WordBasic.FilePrintSetup(Printer:=printPriority2, DoNotSetAsSysDefault:=1)
          Case 3
                 oWordApp.WordBasic.FilePrintSetup(Printer:=printPriority3, DoNotSetAsSysDefault:=1)
          Case 4
                 oWordApp.WordBasic.FilePrintSetup(Printer:=printPriority4, DoNotSetAsSysDefault:=1)
          Case 5
                 oWordApp.WordBasic.FilePrintSetup(Printer:=printPriority5, DoNotSetAsSysDefault:=1)
   End Select

   oTargetDoc = oWordApp.Documents.Open(SQLdr("DocumentName") & ".doc")
   oWordApp.PrintOut()
   oWordApp.Documents.Close()
   oWordApp.Quit()

Answer 1

Here is how you can run this method in a Background thread: http://msdn.microsoft.com/en-us/library/cc221403(v=vs.95).aspx

ps the most likely reason your seeing high CPU is because of the document size, but you’ll also see high memory because your not cleaning up your objects, eg:

Marshal.ReleaseComObject(app)

Here’s an article to understand the best practice when it comes to native memory management via managed code: http://jake.ginnivan.net/vsto-com-interop