BUG: Printer Error When Printing from RTF Control

• Standard, Professional and Enterprise Editions of Microsoft Visual Basic, 32-bit only, for Windows, version 4.0

SYMPTOMS

After printing from a Rich Text Box control, Visual Basic 4.0 raises error 482 - "Printer Error". This error can occur when exiting a Visual Basic application or when executing the EndDoc method of the Printer object.

WORKAROUND

After printing from a RTF control, executing an EndDoc will exhibit this problem. Visual Basic executes an automatic Printer.EndDoc if a program stops execution with buffered data. Even though this error is raised, the pages do print correctly. The workaround for this problem is to trap error 482 and simply ignore it. The example below contains code to demonstrate this technique.

STATUS

Microsoft has confirmed this to be an issue in the Microsoft products listed at the beginning of this article. We are researching this problem and will post more information here in the Microsoft Knowledge Base when it becomes available.

MORE INFORMATION

Steps to Reproduce

1. Start Visual Basic, or, if it is already running, choose New Project from the File Menu.

2. Add an RTF control and a command button to the form.

3. Insert the following code in the Command1_Click event.

      Private Sub Command1_Click()
          Printer.Print ""
          RichTextBox1.SelPrint Printer.hDC
          Printer.EndDoc
      End Sub
   
   

4. Run the application.

5. Enter some text in the RTF text box, and click on the command button to print. The program will stop and an error dialog box, complaining of the above mentioned error, will be displayed. Clicking on the "Debug" button in the error dialog box will show that the line of code that execution stopped on was the call to EndDoc.

   Private Sub Command1_Click()
       Printer.Print ""
       RichTextBox1.SelPrint Printer.hDC

       On Error GoTo EndDocError
       Printer.EndDoc
       On Error GoTo 0

       Exit Sub

   EndDocError:
       If Err.Number = 482 Then
           'do nothing
       Else
           Err.Raise Err.Number
       End If
   End Sub

Additional Note

The RTF sample application included with the Visual Basic 4.0 MSDN Starter Kit was written using a different version of the RTF control than the one that shipped with Visual Basic 4.0. As a result, the above fix is not implemented in the code for that sample application. The RTF sample can be fixed by the same method outlined above; simply trap error 482 and ignore it.