Setting the printer from the Drawing print manager gives a generic error

[dwlawrence]

In the following code, attempting to set the printer from the DrawingPrintManager gives an error and then continues onto using the default system printer. This error has come up as a "Class Not Registered error, but is typically an Unspecified Error. 

If you hard code in the string to, i.e., "Microsoft Print to PDF" etc., it works without any problems. It's just when setting the printer to the user selection after being certain it's cast to a String data type, that it catches the errors. I left the MessageBox in that shows what the user's selected item is from the drop down box.

<Start Code>

Imports System.Text

Imports System.Windows.Forms

AddReference "System.Drawing.dll"

Sub Main()

'Define the active document and check to make sure it's a DrawingDocument type and, if not, send the user a Msg and bail out

Dim oDoc As DrawingDocument = ThisApplication.ActiveDocument

If oDoc.DocumentType <> DocumentTypeEnum.kDrawingDocumentObject Then

MessageBox.Show("Please Open a Drawing File to Print", "NOT A DRAWING DOCUMENT")

Exit Sub

End If

Call SetUpDialogForm(oDoc)

End Sub

Sub SetUpDialogForm(oDoc As DrawingDocument)

Dim oPrintMgr As Inventor.DrawingPrintManager = oDoc.PrintManager

Dim printerList As New StringBuilder()

printerList.AppendLine("Installed Printer List: ").AppendLine()

'Get Installed printers

For Each printer As String In System.Drawing.Printing.PrinterSettings.InstalledPrinters

printerList.AppendLine(printer)

Next

Dim strResults As String = printerList.ToString

'MessageBox.Show(strResults, "Printers Available")

' Convert StringBuilder to a string array

Dim printers() As String = printerList.ToString().Split(System.Environment.NewLine)

' Create the pull-down form 

Dim pullDownForm As New Form()

pullDownForm.Text = "Select Printer From List"

pullDownForm.Size = New Drawing.Size(400, 150)

' Center the form on the screen

pullDownForm.StartPosition = FormStartPosition.CenterScreen

' Create and configure the ComboBox

Dim comboBox As New ComboBox()

comboBox.Items.AddRange(printers)

comboBox.DropDownStyle = ComboBoxStyle.DropDownList

comboBox.Size = New Drawing.Size(300, 30)

' Center the ComboBox horizontally

comboBox.Location = New Drawing.Point((pullDownForm.ClientSize.Width - comboBox.Width) / 2, 30)

' Create and configure the OK button

Dim okButton As New Button()

okButton.Text = "OK"

okButton.Size = New Drawing.Size(75, 30)

' Position the OK button below the ComboBox by 10 pixels

okButton.Location = New Drawing.Point((pullDownForm.ClientSize.Width - okButton.Width) / 2 - 40, comboBox.Bottom + 10)

' Create and configure the Cancel button

Dim cancelButton As New Button()

cancelButton.Text = "Cancel"

cancelButton.Size = New Drawing.Size(75, 30)

' Position the Cancel button to the right of the OK button

cancelButton.Location = New Drawing.Point(okButton.Right + 10, okButton.Top)

' Define what happens when the OK button is clicked

AddHandler okButton.Click, Sub(sender, E)

                               ' Check if a choice has been selected

                               If comboBox.SelectedIndex = -1 Then

                                   ' If no selection, close the form affter letting the user know

   MessageBox.Show("No Printer Selected. Exiting", "EXITING. TRY AGAIN", MessageBoxButtons.OK, MessageBoxIcon.Stop)

                                   pullDownForm.Close()

                               Else

                                   Dim selectedChoice As String = comboBox.SelectedItem.ToString()

'Set the printer options and use Arch D size

With oPrintMgr 

Try

'Print out selected choice for debugging

MessageBox.Show("Selected Printer: " + selectedChoice, "Selected Printer")

'Attempt to set the printer

.Printer = selectedChoice.ToString()

Catch ex As System.Exception

MessageBox.Show("Error: " + ex.Message, "ERROR OCCURED SETTING PRINTER")'**Error: 'Class not registered' may mean the COM Object isn't properly registered

End Try

.AllColorsAsBlack = True

.Orientation = kLandscapeOrientation

.PaperSize = kPaperSizeCustom

.PaperHeight = 24

.PaperWidth = 36

.SubmitPrint()

End With

                                   ' Close the form after selection

                                   pullDownForm.Close()

                               End If

                           End Sub

' Define what happens when the Cancel button is clicked

AddHandler cancelButton.Click, Sub(sender, E)

                                  ' Close the form when Cancel is clicked

                                  pullDownForm.Close()

                               End Sub

' Handle the form's closing event to detect when the user hits the X

AddHandler pullDownForm.FormClosing, Sub(sender, e)

                                       If e.CloseReason = CloseReason.UserClosing Then

                                           ' Set the DialogResult to Cancel when the user clicks the "X"

                                           pullDownForm.DialogResult = DialogResult.Cancel

                                       End If

                                   End Sub

' Add controls to the form

pullDownForm.Controls.Add(comboBox)

pullDownForm.Controls.Add(okButton)

pullDownForm.Controls.Add(cancelButton)

' Show the form to the user

pullDownForm.ShowDialog()

End Sub

<End Code>

[dwlawrence · Accepted solution]

Thanks to @gkniksch_aep, who found it was StringBuilder messing with the string. So making it a List(Of String) did the trick for anyone that faces this one.