Error when creating an instance of Word in VB.net

问题

I am getting an error when I run this app in VS 2010 (it works fine in VS 2008)

Private Sub GenerateInvoice()

Dim emptyObject As Object = System.Reflection.Missing.Value

Dim wordApp As New Word.Application
wordApp.Visible = True

Dim InvoiceDoc As New Word.Document
InvoiceDoc = wordApp.Documents.Add(InvoicePath, emptyObject, emptyObject, emptyObject)

Dim totalFields As Integer = 0

For Each mergeField As Word.Field In InvoiceDoc.Fields

The error occurs at the For Each line

"Object reference not set to an instance of an object."

Am I missing something here?

回答1:

Maybe the InvoicePath used in the instance run via VS2010 is invalid and so the call to Documents.Add fails?

Are you running both VS2010 and VS2008 on the same machine? And is the InvoicePath set to the exact same path in both instances?

回答2:

Try

 Dim InvoiceDoc As Word.Document
 wordApp.Documents.Add(InvoicePath, emptyObject, emptyObject, emptyObject)
 InvoiceDoc=wordApp.ActiveDocument

来源：https://stackoverflow.com/questions/4184593/error-when-creating-an-instance-of-word-in-vb-net