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Disable close button

Can we disable the close button on a form ? I can remove the minimize/maximize, but cant find anyway to disable the close button.

[129 byte] By [WongJunnKit] at [2007-12-16]

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# 1

private sub thanks()
{
Dim frm as new Form2
frm.MinimizeBox = False
frm.MaximizeBox = False
frm.ControlBox = False
frm.Show()
}

this code would make all that go away in this example i was just creating a new form off a button but you could put this in the load event of your form and it would launch that way

wacko at 2007-9-8 >

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# 2

Thanks for reply, but thats not what I want, if i set the controlbox=false, all maximize, minimize, close and the form icon will be gone, I just the close to be gone or disabled.

WongJunnKit at 2007-9-8 >

# 3

well after doing a little research I have found the answer... here is the code in a CloseButton Class that should do the trick

Option Explicit On
Option Strict On

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 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
End Sub

End

Class

then just call this on a form load or whatever... it worked for me when i tested it

wacko at 2007-9-8 >

# 4

Not sure if you can make it go away, but you can disable the close using the FormClosing event.

This code allows the form to be closed by clicking a button on the form, but not by clicking the form's close button.

Private okToClose As Boolean = False

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

okToClose = True

Me.Close()

End Sub

Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing

If Not okToClose Then

e.Cancel = True

End If

End Sub

Robert

RobertGreen at 2007-9-8 >

# 5

Here's an alernate method:

Protected Overrides ReadOnly Property CreateParams() As CreateParams

Get

Dim cp As CreateParams = MyBase.CreateParams

Const CS_NOCLOSE As Integer = &H200

cp.ClassStyle = cp.ClassStyle Or CS_NOCLOSE

Return cp

End Get

End Property

TaDa at 2007-9-8 >

# 6

I think that the following is what you are wanting, try it please!

Create a new project and insert a new class that must have the following

Public Class close_button

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

Private Declare Function GetSystemMenu Lib "user32" (ByVal hwnd As Int32, ByVal bRevert As Boolean) As Int32

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

Public Sub enable(ByVal form As Form)

EnableMenuItem(GetSystemMenu(form.Handle, False), SC_CLOSE, MF_ENABLED)

End Sub

Public Sub disable(ByVal form As Form)

EnableMenuItem(GetSystemMenu(form.Handle, False), SC_CLOSE, MF_GRAYED)

End Sub

End Class

then you are ready to use, on the form1 create 2 buttons and change do text to "enable" and "disable" respectivly, the code must be the following:

Public Class Form1

Dim close_button As New close_button

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

close_button.enable(Me)

End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

close_button.disable(Me)

End Sub

End Class

if you want to use with another form put for example Form2.Handle intead of Me

CarlosAdrianoPortes at 2007-9-8 >

# 7

Hello,

I have this working fine. I put the close_button.enable(Me) method in my load event. However, when I minimized the form, then maximized it, my close button went back to enabled. Is there a workaround for this?

Thanks.

Rashar at 2007-9-8 >

# 8

Yes, use my CreateParams method.

TaDa at 2007-9-8 >

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