Show/Hide MDIForm in the taskbar

[Chris]

Use the SetWindowPosAPI will do.

Option Explicit
Private Declare Function SetWindowPos Lib "user32" (ByVal hwnd As Long, ByVal hWndInsertAfter As Long, ByVal x As Long, ByVal y As Long, ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long) As Long
Private Const SWP_SHOWWINDOW = &H40
Private Const SWP_HIDEWINDOW = &H80
Private Const SWP_NOMOVE = &H2
Private Const SWP_NOSIZE = &H1

Private Sub Command1_Click()
'Hide
SetWindowPos MDIForm1.hwnd, HWND_TOP, 0, 0, 0, 0, SWP_NOMOVE Or SWP_NOSIZE Or SWP_HIDEWINDOW
End Sub

Private Sub Command2_Click()
'Show
SetWindowPos MDIForm1.hwnd, HWND_TOP, 0, 0, 0, 0, SWP_NOMOVE Or SWP_NOSIZE Or SWP_SHOWWINDOW
End Sub