Option Explicit On
Imports Microsoft.Office.Interop
Imports System.Windows.Forms
Imports System.IO
'**********************************************
'****
'****   Problem mit Delegate Invoke
'****   beim oeffnen der zweiten Datei
'****   Form haengt sich auf ohne Exception
'****
'**********************************************
Public Class frmTestTest
    Private Delegate Sub DelSetTextLabel(ByVal lblText As String)
    Private appWord As Word.Application
    Private docWord As Word.Document
    Private folder As String
    Private counter As Byte
 
    Public Shared Sub Main()
        frmTestTest.Show()
    End Sub
 
    Private Sub frmTestTest_Load(ByVal sender As Object, _
                                     ByVal e As System.EventArgs) Handles _
                                     MyBase.Load
        lblTest.Text = "Test"
        folder = Environment.GetFolderPath(Environment.SpecialFolder.Personal) _
          'Eigene Dateien
        appWord = New Word.Application
        appWord.Visible = True
        AddHandler appWord.DocumentChange, AddressOf DocEvent
        'wenn die Word-Dokumente hier (ohne Button) geladen werden geht alles
        'docWord = appWord.Documents.Open(folder & "\" & "AAATest_1.docx")
        'docWord = appWord.Documents.Open(folder & "\" & "AAATest_2.docx")
        'docWord = appWord.Documents.Open(folder & "\" & "AAATest_3.docx")
    End Sub
 
    Private Sub DocEvent()
        Dim text As String
        text = appWord.ActiveDocument.Name
        Me.Invoke(New DelSetTextLabel(AddressOf setLabelText), text)
    End Sub
 
    Private Sub setLabelText(ByVal lblText As String)
        lblTest.Text = lblText
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        counter += 1
        If counter = 1 Then docWord = appWord.Documents.Open(folder & "\" & _
          "AAATest_1.docx")
        If counter = 2 Then docWord = appWord.Documents.Open(folder & "\" & _
        "AAATest_2.docx") 'nach dem laden hängt das Formular
        If counter = 3 Then docWord = appWord.Documents.Open(folder & "\" & _
        "AAATest_3.docx")
    End Sub
 
End Class