Enable/Disable the form Close X button

[davidrobin]

Credit for this code goes to crptcblade

The following code can be used to enable or disable the X button on the control box of a form.

The following form goes in a module

Public Declare Function GetSystemMenu Lib "user32" (ByVal hwnd  _
As Long, ByVal bRevert As Long) As Long
Public Declare Function RemoveMenu Lib "user32" (ByVal hMenu _
 As Long, ByVal nPosition As Long, ByVal wFlags As Long) As Long
Public Declare Function DrawMenuBar Lib "user32" (ByVal hwnd  _
As Long) As Long

Private Const MF_BYCOMMAND = &H0&
Private Const SC_CLOSE = &HF060&

Public Sub SetXState(frm As Form, blnState As Boolean)
    Dim hMenu As Long

    hMenu = GetSystemMenu(frm.hwnd, blnState)
    Call RemoveMenu(hMenu, SC_CLOSE, MF_BYCOMMAND)
    Call DrawMenuBar(frm.hwnd)

End Sub

The enabling and disabling is performed like so

Private Sub Command1_Click()
    If opt(0).Value = True Then 
        SetXState Me, True   'enable the X button
    ElseIf opt(1).Value = True Then
        SetXState Me, False  'disable the X button
    End If
End Sub