Public Class Form1
    Public Declare Function EnumWindows Lib "user32.dll" (ByVal lpEnumFunc As _
      EnumWindowsProc, ByVal lParam As Int32) As Int32
    Public Declare Function IsWindowVisible Lib "user32.dll" (ByVal hwnd As _
    IntPtr) As Boolean
    Public Delegate Function EnumWindowsProc(ByVal hwnd As IntPtr, ByVal lParam _
    As Int32) As Boolean
    Public Declare Function GetWindowText Lib "user32.dll" Alias _
    "GetWindowTextA" (ByVal hwnd As IntPtr, ByVal lpString As String, ByVal cch _
    As Int32) As Int32
    Public Declare Function GetWindowTextLength Lib "user32.dll" Alias _
    "GetWindowTextLengthA" (ByVal hwnd As IntPtr) As Int32
    Public Declare Function GetWindowLong Lib "user32.dll" Alias _
    "GetWindowLongA" (ByVal hwnd As IntPtr, ByVal nIndex As Int32) As Int32
    Public Declare Function GetParent Lib "user32.dll" (ByVal intptr As IntPtr) _
    As IntPtr
    Public Const GWL_HWNDPARENT As Int32 = -8
    Private newwindowlist As List(Of String)
 
    Declare Function SendMessage Lib "user32.dll" _
  Alias "SendMessageA" ( _
  ByVal hWnd As Long, _
  ByVal Msg As Long)
 
    Private Function EnumWinProc(ByVal hwnd As IntPtr, ByVal lParam As Int32) _
      As Boolean
        If IsWindowVisible(hwnd) Then
            If GetParent(hwnd) = IntPtr.Zero Then
                If GetWindowLong(hwnd, GWL_HWNDPARENT) = 0 Then
                    Dim str As String = String.Empty.PadLeft( _
                      GetWindowTextLength(hwnd) + 1)
                    GetWindowText(hwnd, str, str.Length)
                    If Not String.IsNullOrEmpty(str.Substring(0, str.Length - _
                      1)) Then newwindowlist.Add(str.Substring(0, str.Length - _
                      1))
                End If
            End If
        End If
        EnumWinProc = True
    End Function
 
    Private Sub RefreshWindowList()
        newwindowlist = New List(Of String)
        EnumWindows(AddressOf EnumWinProc, CInt(True))
    End Sub
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        RefreshWindowList()
        For Each item As String In newwindowlist
            If item.EndsWith(" - Chat") Then 'nach dem Channel Fenster suchen
                ListBox1.Items.Add(item)
            End If
        Next
    End Sub
 
    Private Sub Button1_Click() 'Liste erneuern
 
        RefreshWindowList()
        For Each item As String In newwindowlist
            If item.EndsWith(" - Chat") Then 'nach dem Channel Fenster suchen
                ListBox1.Items.Add(item)
            End If
        Next
    End Sub
End Class