Private WithEvents workflowRuntime As WorkflowRuntime = Nothing
Private workflowInstance As WorkflowInstance = Nothing
Private WithEvents waitHandle As New AutoResetEvent(False)
Public Sub main()
   Dim WorkflowType As Type = GetType(Workflow4)
   Dim Params As New Dictionary(Of String, Object)
   Dim Fields As New Dictionary(Of String, String)
   Params.Add("Fields", Fields)
   ' Start the workflow
   workflowRuntime = New WorkflowRuntime
   workflowInstance = _
      workflowRuntime.CreateWorkflow(WorkflowType, Params)
   workflowInstance.Start()
   waitHandle.WaitOne()

<STAThread()> Protected Overrides Function Execute _
  (ByVal executionContext As ActivityExecutionContext) _
  As ActivityExecutionStatus

  Dim Status As ActivityExecutionStatus

  ' Open the target document or template
  If String.IsNullOrEmpty(Me.InputDocument) Then
    If Me.Fields _
      IsNot Nothing AndAlso Me.Fields.ContainsKey(Me.Name) Then  
      ' Use a field named for *this* activity if it is a document 
      Dim NameValue As String = Fields(Me.Name)
      Select Case System.IO.Path.GetExtension(NameValue).ToLowerInvariant
        Case ".doc", ".docx", ".dot", ".dotx"
          InputDocument = NameValue
        Case Else
          Throw New ArgumentException( _ 
   "Input Document Invalid or Missing")
      End Select
    End If
  End If

  ' Create or open the required document from an input 
  ' document or template
  WordFiller = New WordInterface(InputDocument, Fields)

  ' Production workflow may not want to show the document
  If Me.Fields.ContainsKey("Visible") Then
    Boolean.TryParse(Me.Fields("Visible"), WordFiller.Visible)
  End If

  ' Get success or failure from the Word Interface class
  Dim Success As Boolean = WordFiller.FillInDocument()
  WordApp = WordFiller.WordApp

  If Success Then
    ' Find the target output document
    If String.IsNullOrEmpty(Me.OutputDocument) Then
      If Me.Fields.ContainsKey("Output") Then
        Dim NameValue As String = Fields("Output").ToString

        If NameValue.EndsWith(".doc", _
          StringComparison.CurrentCultureIgnoreCase) _
          OrElse NameValue.EndsWith(".docx", _
          StringComparison.CurrentCultureIgnoreCase) Then

          ' Set the document property to the provided name
          Me.OutputDocument = NameValue
        Else 'Force .doc suffix
          Me.OutputDocument = NameValue & ".doc"
        End If
      End If
    End If

    ' Save the output 
    WordApp.ActiveDocument.SaveAs(Me.OutputDocument)

    Cleanup()

    Status = ActivityExecutionStatus.Closed
    executionContext.CloseActivity()
  Else
    Cleanup()

    Status = ActivityExecutionStatus.Closed
    executionContext.CancelActivity(Me)
  End If

  Return Status
End Function

Public Overrides Function FillInDocument() As Boolean
  Dim Status As Boolean = False
  _WordApp = New Word.Application
  WordApp.Visible = Visible

  ' Check for template
  Select Case Path.GetExtension(Document).ToLowerInvariant
    Case ".dot", ".dotx"
      _WordDocument = WordApp.Documents.Add(Document)
    Case ".doc", ".docx"
      _WordDocument = WordApp.Documents.Open(FileName:=Document, _
        ReadOnly:=True)
  End Select

  ' Determine dictionary variables to use 
  ' based on bookmarks in the document matching Fields entries
  If WordDocument IsNot Nothing _
    AndAlso WordDocument.Bookmarks.Count > 0 Then

    Dim BookMark As Word.Bookmark = Nothing
    For i As Integer = 1 To WordDocument.Bookmarks.Count
      BookMark = WordDocument.Bookmarks(i)
      Dim BookMarkName As String = BookMark.Name
      Dim rng As Word.Range = BookMark.Range
      If Me.Fields.ContainsKey(BookMarkName) Then
        rng.Text = Fields(BookMarkName).ToString   
        'This results in the bookmark being lost, it needs to be replaced
        WordApp.ActiveDocument.Bookmarks.Add(BookMarkName, rng)
      Else
        ' Handle special case(s)
        Select Case BookMark.Name
          Case "FullName"
            rng.Text = GetFullName(Fields)
        End Select
      End If
    Next
      Status = True
  Else
    Status = False
  End If

  Return Status
End Function

<IfElseActivity x:Name="CustomerScenario">
  <IfElseBranchActivity x:Name="ProcessApproval">
    <IfElseBranchActivity.Condition>
    <CodeCondition Condition="ifElseBranchActivity1Condition" />
    </IfElseBranchActivity.Condition>
    <CodeActivity x:Name="codeActivity1" ExecuteCode=
      "{ActivityBind Workflow4,Path=codeActivity1_ExecuteCode1}" />
    <ns1:WordFormFill Description="Fill in fields in a Word document"
      x:Name="WriteCustomerLetter" Fields="{x:Null}" 
      OutputDocument="{x:Null}" 
      InputDocument=" C:\MSDN Workflow\Templates\Customer Letter.doc" />
</IfElseBranchActivity>

Public Sub ifElseBranchActivity1Condition(ByVal sender As Object, _
  ByVal e As ConditionalEventArgs)
  ' Look for status matching desired value for *this* branch
  If Me.Fields.ContainsKey("Status") AndAlso _
    Me.Fields("Status") = "Approved" Then

    ' Look for a WordFormFill activity as a child to *this* branch
    Dim target As Activity = _
      WorkflowUtilities.FindActivityByType( _
      GetType(WordFormActivity.WordFormFill), _
      (DirectCast(sender, Activity)))

    If target IsNot Nothing Then
      Dim TargetActivity As WordFormActivity.WordFormFill = _
        DirectCast(target, WordFormActivity.WordFormFill)
      TargetActivity.Fields = Me.Fields
      ' Set input document by using field named for target activity
      TargetActivity.Fields.Add(TargetActivity.Name, Me.InputDocument)
      e.Result = True

    Else
      e.Result = False
    End If

  Else
    e.Result = False
  End If

End Sub