Hi All,

I would like to disable/enable the close button('X') on the window form.

Does someone know how to do?

Thanks,

walker

Hi, slow walker

There are two ways to do so:

Method 1(simplest way): Set form.controlBox to false in form class

 this.ControlBox = false;

(However this method will also erase the maximum and minimum box.)

Method 2: Interoperate with the windows API provided

[DllImport("user32", EntryPoint = "GetSystemMenu", SetLastError = true,
CharSet = CharSet.Unicode, ExactSpelling = true,
CallingConvention = CallingConvention.Winapi)]
private static extern IntPtr GetSystemMenu(IntPtr hwnd, int bRevert);

[DllImport("user32", EntryPoint = "DeleteMenu", SetLastError = true,
CharSet = CharSet.Unicode, ExactSpelling = true,
CallingConvention = CallingConvention.Winapi)]
private static extern int DeleteMenu(IntPtr hMenu, int nPosition, int wFlags);

[DllImport("user32", EntryPoint = "GetMenuItemCount", SetLastError = true,
CharSet = CharSet.Unicode, ExactSpelling = true,
CallingConvention = CallingConvention.Winapi)]
private static extern int GetMenuItemCount(IntPtr hMenu);

int mf_byposition = 0x00000400;

And use as:

IntPtr longVal = GetSystemMenu(this.Handle, 0);
int longCount = GetMenuItemCount(longVal);

DeleteMenu(longVal, longCount - 1, mf_byposition);

(remember to put the reference at the beginning: using System.Runtime.InteropServices)

Thank you

Here is a simple and easy way that i used in my form.

You will need the Runtime.InteropServices namespace included in ur code.

Importing the WIN32 API

[DllImport("user32")]
private static extern int GetSystemMenu(IntPtr hWnd, bool bRevert);

[DllImport("user32")]
private static extern bool DeleteMenu(int hMenu, int uPosition, int uFlags);

private int s_SystemMenuHandle = 0;

private void cmdDisableX_Click(object sender, EventArgs e)
{
this.s_SystemMenuHandle = GetSystemMenu(this.Handle, false);
DeleteMenu(this.s_SystemMenuHandle, 6, 1024);
}

private void cmdEnableX_Click(object sender, EventArgs e)
{
this.s_SystemMenuHandle = GetSystemMenu(this.Handle, true);
DeleteMenu(this.s_SystemMenuHandle, 6, 1024);
}

You are done. Enjoy!!!

Regards

Suan Ngaihte

There's no out-of-box support from C# for this. You'll need to use win32 calls. A simple (and using C# only) solution is to set the ControlBox property of the form to false - but this removes everything - icon, min button, max button, and the close button.

Hi,

It seems ,it's not possible to do this with any property or function.

But u can implement logic tocancel the closingthe event , in

FormClosing(object sender, FormClosingEventArgs e) function

My idea:

//Some how u have to confirm that user has pressed the X button on the form

// It can be decided by setting a flag, where ever use this.Close(). So , if the flag is set, means, the form is getting closed by some other action other than pressing this X button on the form.

//If the flag is not set ->implies , user has pressed the X button on the form , so can cancel the event , using

e.Cancel = true; - instruction

I tested with a button on form.

In buttonclick_handler, i set the flag - CanCloseForm= true;

and called this.Close()).

In the form_closing event i checked this flag

private void Form1_FormClosing(object sender, FormClosingEventArgs e)

{

e.Cancel = !CanCloseForm;

}

Thanx,

Ch.T.Gopi Kumar.

}

Hi, slow walker

There are two ways to do so:

Method 1(simplest way): Set form.controlBox to false in form class

 this.ControlBox = false;

(However this method will also erase the maximum and minimum box.)

Method 2: Interoperate with the windows API provided

[DllImport("user32", EntryPoint = "GetSystemMenu", SetLastError = true,
CharSet = CharSet.Unicode, ExactSpelling = true,
CallingConvention = CallingConvention.Winapi)]
private static extern IntPtr GetSystemMenu(IntPtr hwnd, int bRevert);

[DllImport("user32", EntryPoint = "DeleteMenu", SetLastError = true,
CharSet = CharSet.Unicode, ExactSpelling = true,
CallingConvention = CallingConvention.Winapi)]
private static extern int DeleteMenu(IntPtr hMenu, int nPosition, int wFlags);

[DllImport("user32", EntryPoint = "GetMenuItemCount", SetLastError = true,
CharSet = CharSet.Unicode, ExactSpelling = true,
CallingConvention = CallingConvention.Winapi)]
private static extern int GetMenuItemCount(IntPtr hMenu);

int mf_byposition = 0x00000400;

And use as:

IntPtr longVal = GetSystemMenu(this.Handle, 0);
int longCount = GetMenuItemCount(longVal);

DeleteMenu(longVal, longCount - 1, mf_byposition);

(remember to put the reference at the beginning: using System.Runtime.InteropServices)

Thank you

Here is a simple and easy way that i used in my form.

You will need the Runtime.InteropServices namespace included in ur code.

Importing the WIN32 API

[DllImport("user32")]
private static extern int GetSystemMenu(IntPtr hWnd, bool bRevert);

[DllImport("user32")]
private static extern bool DeleteMenu(int hMenu, int uPosition, int uFlags);

private int s_SystemMenuHandle = 0;

private void cmdDisableX_Click(object sender, EventArgs e)
{
this.s_SystemMenuHandle = GetSystemMenu(this.Handle, false);
DeleteMenu(this.s_SystemMenuHandle, 6, 1024);
}

private void cmdEnableX_Click(object sender, EventArgs e)
{
this.s_SystemMenuHandle = GetSystemMenu(this.Handle, true);
DeleteMenu(this.s_SystemMenuHandle, 6, 1024);
}

You are done. Enjoy!!!

Regards

Suan Ngaihte

This is how I've disableda Windows Formsclose box in C#:

using System.Runtime.InteropServices;

// Declare P/Invoke methods

[ DllImport("user32")]

private static extern IntPtr GetSystemMenu(IntPtr hWnd, bool revert);

[DllImport("user32")]

private static extern int EnableMenuItem(IntPtr hWndMenu, int itemID, int enable);

// Declare constants (from winuser.h) to pass to the methods

private const int SC_CLOSE= 0xF060;

private const int MF_ENABLED = 0x0000;

private const int MF_GREYED = 0x0001;

private bool closeBoxEnabled = true;

public bool CloseEnabled

{

get { return closeBoxEnabled; }

set {

EnableMenuItem(GetSystemMenu(this.Handle, false), SC_CLOSE,

value ? MF_ENABLED : MF_GREYED);

closeBoxEnabled = value;

}

}

If you search for GetSystemMenu() in MSDN you'll find this solution described.