Microsoft Office 2000/Visual Basic Programmer's Guide

Displaying Help for Custom Error Messages

The Raise method of the Err object has optional helpfile and helpcontext arguments that set the HelpFile and HelpContext properties of the Err object to the specified Help file name and context ID when your custom error is triggered. If the error trap in your procedure then passes these values to the MsgBox function, you can add a Help button to call additional Help from your error message dialog box. The following code example shows how to do this:

Sub ShowErrorHelp()
   Dim strAppPath As String
   
   strAppPath = ActiveDocument.Path
   
   On Error GoTo ShowErrorHelp_Err
   Err.Raise Number:=vbObjectError + 1234, _
             Source:="Sub ShowErrorHelp", _
             Description:="This error has a reason.", _
             HelpFile:=strAppPath & "\sample.chm", _
             HelpContext:=2003

ShowErrorHelp_End:
   Exit Sub

ShowErrorHelp_Err:
   MsgBox Prompt:=Err.Description, _
          Buttons:=vbMsgBoxHelpButton, _
          HelpFile:=Err.HelpFile, _
          Context:=Err.HelpContext
   Resume ShowErrorHelp_End
End Sub

The ShowErrorHelp procedure is available in the modHTMLHelp module in the WordHelp.doc in the ODETools\V9\Samples\OPG\Samples\CH13 subfolder on the Office 2000 Developer CD-ROM.

The helpfile and helpcontext arguments of the Raise method support using a compiled HTML Help file in all Office applications, including Word and Access. There is no need to use the HtmlHelp API to display a Help topic in a .chm file when you are using the Raise method to return a Help file name and context ID in Word and Access.