Inherits System.Windows.Forms.NativeWindow
 
    ' Das sind die Ereignisse aus WParam.
    ' Uns interessiert nur, ob ein Laufwerk hinzugekommen ist oder 
    '  entfernt wurde.
    Public Event DriveArrived(ByVal sender As Object, ByVal e As _
      System.IO.DriveInfo)
    Public Event DriveRemoved(ByVal sender As Object, ByVal e As _
    System.IO.DriveInfo)
 
    ' Die Struktur für OEM.
    ' Wird über LParam gefüllt.
    ' USB-Sticks laufen alle hier auf.
    Private Structure DEV_BROADCAST_OEM
        Dim dbco_size As Integer
        Dim dbco_devicetype As Integer
        Dim dbco_reserved As Integer
        Dim dbco_identifier As Integer
        Dim dbco_suppfunc As Integer
    End Structure
 
    ' Die Struktur für Volumes.
    ' Wird über LParam gefüllt.
    Private Structure DEV_BROADCAST_VOLUME
        Dim dbch_size As Integer
        Dim dbch_devicetype As Integer
        Dim dbch_reserved As Integer
        Dim dbcv_unitmask As Integer
        Dim dbcv_flags As Short
    End Structure
 
    ' Die Struktur für den Header.
    ' Wird über LParam gefüllt.
    Private Structure DEV_BROADCAST_HDR
        Dim dbch_size As Integer
        Dim dbch_devicetype As Integer
        Dim dbch_reserved As Integer
    End Structure
 
    ' Das sind die Konstanten der Gerätetypen
    ' Vorsicht die Gerätetypen Variablen in den Strukturen sind vom Typ Integer.
    ' IntelliSense kann das nicht auflösen.
    Private Enum DeviceType
        OEM = 0
        DEVNODE = 1
        VOLUME = 2
        PORT = 3
        NET = 4
        DEVICEINTERFACE = 5
        HANDLE = 6
    End Enum
 
 
 
    ' Windowmessage DeviceChange
    Private Const WM_DEVICECHANGE As Integer = &H219
 
    'Die beiden Ereignisse, die für uns von Bedeutung sind.
    Private Const DBT_DEVICEARRIVAL As Integer = &H8000
    Private Const DBT_DEVICEREMOVECOMPLETE As Integer = &H8004
 
    ' Dies ist der Dreh- und Angelpunkt der Klasse. - Hier bekommen wir die 
    '  Messages mit.
    ' In unserm Fall interessiert uns nur die WM_DeviceChange-Nachricht
    Protected Overrides Sub WndProc(ByRef m As Message)
        If m.Msg = WM_DEVICECHANGE Then
            Debug.WriteLine(GetSerialNumber(Me.HandleHeader(m)))
        End If
        MyBase.WndProc(m)
    End Sub
 
    ' Hier schauen wir erst mal in den Header und verzweigen dementsprechend
    Private Function HandleHeader(ByRef m As Message) As String
        Dim header As DEV_BROADCAST_HDR
        Dim objHeader As Object = m.GetLParam(header.GetType)
        If Not IsNothing(objHeader) Then
            'Dient nur zur Kennzeichnung, was nicht implementiert ist
            Dim notSupported As Boolean
 
            Select Case header.dbch_devicetype
                Case DeviceType.OEM
                    Return Me.HandleOEM(m).Name
 
                Case DeviceType.DEVNODE
                    notSupported = True
 
                Case DeviceType.VOLUME
                    Return Me.HandleVolume(m).Name
 
                Case DeviceType.PORT
                    notSupported = True
 
                Case DeviceType.NET
                    notSupported = True
 
                Case DeviceType.DEVICEINTERFACE
                    notSupported = True
 
                Case DeviceType.HANDLE
                    notSupported = True
            End Select
        End If
    End Function
 
    Private ActDrive As IO.DriveInfo
    Private bArived As Boolean
    Private bRemoved As Boolean
 
    ' Das Ereignis betrifft ein Volume
    Private Function HandleVolume(ByRef m As Message) As IO.DriveInfo
        Dim volume As DEV_BROADCAST_VOLUME
        Dim objVolume As Object = m.GetLParam(volume.GetType)
 
        If Not IsNothing(objVolume) Then
            volume = DirectCast(objVolume, DEV_BROADCAST_VOLUME)
            Dim di As New IO.DriveInfo(Me.DriveFromMask(volume.dbcv_unitmask))
 
            ' USB-Stick
            StickID = volume.dbch_devicetype
            If di.DriveType = IO.DriveType.Removable Then
                If CInt(m.WParam) = DBT_DEVICEARRIVAL Then
                    'RaiseEvent DriveArrived(Me, di)
                    Return di
 
                    'Debug.WriteLine(GetHDDSerial(StickID))
                End If
            End If
 
            ' USB-Festplatte
            If di.DriveType = IO.DriveType.Fixed Then
                If CInt(m.WParam) = DBT_DEVICEARRIVAL Then
                    'RaiseEvent DriveArrived(Me, di)
                    Return di
                End If
            End If
 
            If CInt(m.WParam) = DBT_DEVICEREMOVECOMPLETE Then
                'RaiseEvent DriveRemoved(Me, di)
                Return di
            End If
        End If
        Return Nothing
    End Function