How to hide only the Close (x) button?

163
votes

I have a modal dialog, and need to hide the Close (X) button, but I cannot use ControlBox = false, because I need to keep the Minimize and Maximize buttons.

I need to hide just Close button, is there any way to do that?

Thanks a lot!

Update: I had permission to disable it, which is simpler :) Thanks all!

5
c#winforms
Could this be what yuo want: [Hide Close Button [X] of Win Forms in C#.NET](sameeramrutia.wordpress.com/2008/09/16/…) just googled: hide close button c#, second result here! =) – Miguel Angelo
Need is a strong word. Where is this requirement coming from? What is the actual requirement - that the user can't terminate the program, or that the UI "looks like it doesn't have a close button"? Because there are other ways around this, and you're going to be hard pressed to completely close off all of them (e.g. task manager, taskkill, possibly alt+f4, etc). I personally wouldn't work too hard at this, because unless you're re-skinning your whole app anyhow, it will be wasted effort, and break user expectations/continuity with other Windows programs. – Merlyn Morgan-Graham
@Sayem it reveals this page, so don't be such a critic. – Brian Graham
Scratch the minimize button off your list as well. Minimizing a modal dialog will automatically make it close. Necessarily so, it is the only window left that's still enabled. When you minimize it, there would not be any window left that can still get the focus so the user can't get back to your program. You are now in "does this still make sense?" territory. It doesn't. – Hans Passant
I'm late to the party but I have the hunch that this requirement comes from a wish to force the user to leave the dialog exclusively in ways which are under control of the user code, most likely form buttons; perhaps one wants to force the user to make an explicit choice. Is "no cancel option" indeed a valid requirement? Can the user not legitimately choose to undo whatever click made the dialog appear? If he can't, or shouldn't: Could simply closing the dialog be interpreted as "no"? – Peter - Reinstate Monica

5 Answers

155
votes

You can't hide it, but you can disable it by overriding the CreateParams property of the form.

private const int CP_NOCLOSE_BUTTON = 0x200;
protected override CreateParams CreateParams
{
    get
    {
       CreateParams myCp = base.CreateParams;
       myCp.ClassStyle = myCp.ClassStyle | CP_NOCLOSE_BUTTON ;
       return myCp;
    }
}

Source: http://www.codeproject.com/KB/cs/DisableClose.aspx

174
votes

We can hide close button on form by setting this.ControlBox=false;

Note that this hides all of those sizing buttons. Not just the X. In some cases that may be fine.

27
votes

Well, you can hide it, by removing the entire system menu:

private const int WS_SYSMENU = 0x80000;
protected override CreateParams CreateParams
{
    get
    {
        CreateParams cp = base.CreateParams;
        cp.Style &= ~WS_SYSMENU;
        return cp;
    }
}

Of course, doing so removes the minimize and maximize buttons.

If you keep the system menu but remove the close item then the close button remains but is disabled.

The final alternative is to paint the non-client area yourself. That's pretty hard to get right.

9
votes

If you really want to hide it, as in "not visible", then you will probably have to create a borderless form and draw the caption components yourself. VisualStyles library has the Windows Elements available. You would also have to add back in the functionality of re-sizing the form or moving the form by grabbing the caption bar. Not to mention the system menu in the corner.

In most cases, it's hard to justify having the "close" button not available, especially when you want a modal form with minimizing capabilities. Minimizing a modal form really makes no sense.

1
votes

Well you can hide the close button by changing the FormBorderStyle from the properties section or programmatically in the constructor using:

public Form1()
{
InitializeComponent();
this.FormBorderStyle = FormBorderStyle.None;
}

then you create a menu strip item to exit the application.

cheers