Need to disable\enable a Form's Close button

9 Comments

• Doesn't seem to work if you maximize a form.
  

• I don't know that you intended it maliciously, but normally when someone helps me on code, I give some credit to them for it...
  

• Thanks for the link love... it's appreciated.
  
  
  
  I mainly blogged about it since I've seen this happen in the past and really haven't seen anyone say anything about it. It was a perfect example of the situation... you thought one thing and it was another. The second portion of the code, although did come from the SDK as to the "what to do", the VB code was done by myself with some additional comments about a bug being reported by people on GDN. It did spend a few hours on it ;-)
  
  
  
  I tried using the tamest verbiage I could find while at the same time making me perspective on the subject as plain as possible ;-)
  
  
  
  Again, thanks for the update and sorry that you ended up being the example in this particular case... but hopefully others will take note and see that this is a problem that is bigger than just one example.
  
  
  
  Also, I'll update my entry stating that you made good ;-)
  

• Justice, this was a misunderstanding and I have addressed it with Cory. I assumed the code came staight from the SDK, thus no link to Cory. A link has since been added. If you look through my past blogs you will see that I do give credit to those that have helped along the way.
  

• Anonymous, sees Cory's link on the mazimize, minimize issue.
  
  
  
  

• Thanks for the help.
  

• but the alt+f4 closed the form. ???
  

• Try this code (my forms inherits from this):
  It solves maximize/minimize and "alt+f4" problems
  The inherited forms have the new "CloseEnable" property
  
  Public Class FormEnabClose
  #Region " Declare "
  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
  #End Region
  
  #Region " Const "
  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
  #End Region
  
  #Region " Var "
  Protected mWinStateAnt As FormWindowState
  Protected mCloseDisable As Boolean
  #End Region
  
  #Region " Prop "
  Public Property CloseEnable() As Boolean
  Get
  Return Not mCloseDisable
  End Get
  Set(ByVal value As Boolean)
  mCloseDisable = Not value
  mWinStateAnt = Me.WindowState
  RefreshCloseButton()
  End Set
  End Property
  #End Region
  
  #Region " Meth "
  Public Sub DisableFormCloseButton()
  ' 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(Me.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 Sub EnableFormCloseButton()
  EnableMenuItem(GetSystemMenu(Me.Handle.ToInt32, 0), SC_CLOSE, MF_BYCOMMAND)
  End Sub
  
  Public Sub RefreshCloseButton()
  If CloseEnable Then EnableFormCloseButton() Else DisableFormCloseButton()
  End Sub
  
  Private Sub FormEnabClose_Resize(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Resize
  If mWinStateAnt = Me.WindowState Then Exit Sub
  RefreshCloseButton()
  mWinStateAnt = Me.WindowState
  End Sub
  
  Private Sub FormEnabClose_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing
  If Not CloseEnable Then
  e.Cancel = True
  Exit Sub
  End If
  End Sub
  #End Region
  End Class
  

• @iluvatarm> Sir thanks for your post. i've got some useful information regarding bypass close event.
  
  here are some novice example.
  This code works with Visual Basic.NET 2008
  VB.NET>WPF Window
  
  Private Sub frmYourFormName_Unloaded(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
  e.Cancel = True
  End Sub
  
  I Hope it will help others. lolz
  thanks and best regards
  
  -mccabero