Adding Macro Code to Word Documents using VB.Net - vb.net

Question

Ok so let me explain in detail.
Suppose there is a word file called "Word.doc"
What I want to do is basically use VB.NET for doing the following things :
Open the word document
Add a macro code
For e.g
Add the following macro code to the Word Document
Sub AutoOpen()
Msgbox
End Sub
And then save this document.
Just remember that I want to insert macro code to a word document not retreive an already present macro code from a document

Answer 1

Here is a simple VBA macro that shows how to use the Word object model to add a macro to a document (VB.NET code will be almost identical).
Sub NewDocWithCode()
Dim doc As Document
Set doc = Application.Documents.Add
doc.VBProject.VBComponents("ThisDocument").CodeModule.AddFromString _
"Sub AutoOpen()" & vbLf & _
" MsgBox ""It works""" & vbLf & _
"End Sub"
End Sub
Note that running this code requires that access to the VBA project object model is trusted (this needs to be enabled in the trust center in the the Word options).

Answer 2

Working with objects in the VBA Editor through the object model requires a reference to the Microsoft Office VBA Extensibility 5.3 object model which you can find in the COM tab of Project/Add References in Visual Studio.
I like to add an Imports statement to the top of the code so that I don't have to always write out the full namespace qualification:
Imports VBE = Microsoft.Vbe.Interop
An AutoOpen macro needs to be a "public" Sub in a normal code module. Assuming you want to add a new code module to the document, use the VBComponents.Add method and specify the enumeration type vbext_ct_StdModule.
By default, the VBE will name the new module "Module#" - an incrementing number. If you ever need to programmatically address this module again (to see if it exists, for example) it would probably be better to assign a name to it.
Code as a string is added using the AddFromString method.
If you're adding code to a document the possibility exists that the document is of type docx, meaning it cannot contain macro code. A document must have the extension docm in order to contain macro code. So you may need to use the SaveAs method on the document to change the file type and the name!
Private Sub InsVbaCode_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles InsVbaCode.Click
'Helper method to get current Word instance or, if none, start one
GetWordProcess()
Dim doc As Word.Document = WordApp.ActiveDocument
Dim vbModule As VBE.VBComponent = doc.VBProject.VBComponents.Add(VBE.vbext_ComponentType.vbext_ct_StdModule)
vbModule.Name = "basAddedCode"
vbModule.CodeModule.AddFromString( _
"Sub AutoOpen()" & vbLf & _
" MsgBox ""Document "" & ActiveDocument.FullName & "" has been opened successfully!""" & vbLf & _
"End Sub")
'doc.Save() or doc.SaveAs to change file type and/or name
End Sub