Disable Close Button .NET WinForms

Just seen some really neat code for doing this at: http://addressof.com/blog/articles/232.aspx

I've also put a copy down below of the bit I used.  I modified Cory Smiths code a little, so you don't have to remember to handle the resize event (a maximise or minimise for some reason renables the close button).  On my modification I automatically add a handler for this in the Class CloseButton.


Public Class CloseButton

    Private Declare Function GetSystemMenu Lib "user32" (ByVal hwnd As Integer, ByVal revert As Integer) As Integer
    Private Declare Function EnableMenuItem Lib "user32" (ByVal menu As Integer, ByVal ideEnableItem As Integer, ByVal enable As Integer) As Integer

    Private Const SC_CLOSE As Integer = &HF060
    Private Const MF_BYCOMMAND As Integer = &H0
    Private Const MF_GRAYED As Integer = &H1
    Private Const MF_ENABLED As Integer = &H0

    Private Sub New()
    End Sub

    Public Shared Sub Disable(ByVal sender As System.Object, ByVal e As System.EventArgs)
        ' The return value specifies the previous state of the menu item (it is either
        ' MF_ENABLED or MF_GRAYED). 0xFFFFFFFF indicates   that the menu item does not exist.
        Dim frm1 As Form
        frm1 = sender

        Select Case EnableMenuItem(GetSystemMenu(frm1.Handle.ToInt32, 0), SC_CLOSE, MF_BYCOMMAND Or MF_GRAYED)
            Case MF_ENABLED
            Case MF_GRAYED
            Case &HFFFFFFFF
                Throw New Exception("The Close menu item does not exist.")
            Case Else
        End Select


    End Sub


    Public Shared Sub Disable(ByVal form As System.Windows.Forms.Form)
        ' The return value specifies the previous state of the menu item (it is either
        ' MF_ENABLED or MF_GRAYED). 0xFFFFFFFF indicates   that the menu item does not exist.
        Select Case EnableMenuItem(GetSystemMenu(form.Handle.ToInt32, 0), SC_CLOSE, MF_BYCOMMAND Or MF_GRAYED)
            Case MF_ENABLED
            Case MF_GRAYED
            Case &HFFFFFFFF
                Throw New Exception("The Close menu item does not exist.")
            Case Else
        End Select

        AddHandler form.Resize, AddressOf CloseButton.Disable

    End Sub

End Class

FAO Cory Smith, if you don't want your code on here contact me and I'll remove it.