Option Explicit

Public Declare Function Shell_NotifyIcon Lib "shell32" Alias _
        "Shell_NotifyIconA" (ByVal dwMessage As Long, pnid As _
        NOTIFYICONDATA) As Boolean

Public Const NIM_ADD = &H0
Public Const NIM_MODIFY = &H1
Public Const NIM_DELETE = &H2
Public Const NIF_MESSAGE = &H1
Public Const NIF_ICON = &H2
Public Const NIF_TIP = &H4

Public Const WM_MOUSEMOVE = &H200
Public Const WM_LBUTTONDOWN = &H201
Public Const WM_LBUTTONUP = &H202
Public Const WM_LBUTTONDBLCLK = &H203
Public Const WM_RBUTTONDOWN = &H204
Public Const WM_RBUTTONUP = &H205
Public Const WM_RBUTTONDBLCLK = &H206

Public Type NOTIFYICONDATA
  cbSize As Long
  hWnd As Long
  uId As Long
  uFlags As Long
  ucallbackMessage As Long
  hIcon As Long
  szTip As String * 64
End Type

Public TIcon As NOTIFYICONDATA

Option Explicit

Dim BildIndex As Integer
Dim Aufbau As Boolean
Dim Shell_NI As Boolean

Private Sub Form_Load()
  BildIndex = -1
  Aufbau = True
End Sub

Private Sub cmdSysTray_Click()
  If tmrBild.Enabled = False Then tmrBild.Enabled = True
  Me.Hide

  TIcon.cbSize = Len(TIcon)
  TIcon.hWnd = picIcon.hWnd
  TIcon.uId = 1&
  TIcon.uFlags = NIF_ICON Or NIF_TIP Or NIF_MESSAGE
  TIcon.ucallbackMessage = WM_MOUSEMOVE
  TIcon.hIcon = picIcon.Picture

  Shell_NotifyIcon NIM_ADD, TIcon
  Shell_NI = True
End Sub

Private Sub PicIcon_MouseMove(Button As Integer, _
      Shift As Integer, X As Single, Y As Single)

  Dim Msg As Long

  Msg = X / Screen.TwipsPerPixelX

  Select Case Msg
    Case WM_LBUTTONDOWN
      Call LeftClickEvent
    Case WM_RBUTTONUP
      Unload Me
  End Select
End Sub

Private Sub tmrBild_Timer()
  If BildIndex = 9 Then BildIndex = -1
  BildIndex = BildIndex + 1

  If Shell_NI Then
    picIcon.Picture = _
          imgLstIcons.ListImages.Item(BildIndex + 1).Picture
    TIcon.hIcon = picIcon.Picture
    Shell_NotifyIcon NIM_MODIFY, TIcon
  End If
End Sub

Private Sub LeftClickEvent()
  picIcon.Picture = imgLstIcons.ListImages.Item(1).Picture
  TIcon.hIcon = picIcon.Picture
  Shell_NotifyIcon NIM_MODIFY, TIcon
  Shell_NotifyIcon NIM_DELETE, TIcon
  tmrBild.Enabled = False
  BildIndex = -1
  Shell_NI = False
  Me.Show
End Sub

Private Sub Form_Unload(Cancel As Integer)
  Shell_NotifyIcon NIM_DELETE, TIcon
  Set frmAniSys = Nothing
End Sub