How can I get the printer HDC

Question

I have a COM component written in C++ that has a Print function. This print function takes the Printer hDC as a parameter that includes all settings to use for the print. Previously, this was called from VB6 code, and Printer.hdc would work here after setting everything on the Printer object.

The code was converted from VB6 to VB.NET, and I have figured out most of things that I need to do. The old Printer object is available through the Microsoft.VisualBasic.PowerPacks.Printing.Compability.VB6.Printer class, but the old hdc property is not supported here.

Can anyone tell me how to get this hdc? Is this hdc the same as GetHdevmode() on a System.Drawing.Printing.PrinterSettings object?

Answer 1

You can get one out of the Graphics object returned by PrinterSettings.CreateMeasurementGraphics(). Use the Graphics.GetHdc() method. Don't forget ReleaseHdc() after printing.

Answer 2

Hdc is not the same as getdevmode, but you can do everything in .net without using hdc. If it saves time using the old code, you can get the hdc from the graphics object and use it as in nobugz's answer. But if you have a graphics object for the printer, it might be simpler to draw directly to the graphics object and skip the hdc altogether.

Answer 3

Here's a similar approach to the one suggested by Hans but it uses a form control. If you are using a form control anyway, this might be a cleaner approach.

Place a PrintDocument from the Windows Forms toolbox to your form.

Then add the following code to handle the print page (as an example):

Private Sub PrintDocument1_PrintPage(ByVal sender As Object, ByVal e As System.Drawing.Printing.PrintPageEventArgs) Handles PrintDocument1.PrintPage
  Dim printerhdc As IntPtr = e.Graphics.GetHdc()

  ' Do whatever you need to do to get the right image
  XYZ.Load file(currentpagenumber)
  XYZ.Render(printerhdc.ToInt64, 25, 25, Width, Height)

  CurrentPageNumber += 1

  If CurrentPageNumber < TotalPageCount Then
   e.HasMorePages = True
  Else
   e.HasMorePages = False
  End If
  e.Graphics.ReleaseHdc(printerhdc)
End Sub

...

'Gather all the files you need and put their names in an arraylist.
'Then issue the print command
PrintDocument1.Print

' You've just printed your files

source: http://www.vbforums.com/showthread.php?247493-Good-ol-Printer-hDC

(source: http://www.vbforums.com/showthread.php?247493-Good-ol-Printer-hDC)