How to Close Child Window Using ALT+F4 Key

[jalzaaal]

Hello All,

I have a MDI form and a some child forms. when I load any child form it is opened in maximized status in mdi form. But when I press Alt+F4 key the MDI form is closed. What I want to do is ... I want is to close the current child form using Alt+F4 key. If I can close the child form Using CTRL+F4 key then it will also be fine.

Can Anyone Help Me????

[RhinoBull]

You can use SendKeys("%{F4}") from a button click but what's the point?

[jalzaaal]

Where Should I write this Sendkeys...?
I dont want to do this on button's event.
what i want is if any child form is currently loaded and user presses Alt+F4 Keys the child form should be unloaded not the Mdi Form.

[the182guy]

If you search on pscode.com/vb you will find code from key logger apps, which will listen for keys pressed, and you could make it so that if alt+f4 is pressed, unload the active child form, or the child form thats in focus.

Chris

[iPrank]

The following code will work (almost). Only problem is that, it can't distinguish between Alt+F4 keypress and Close button click.

Private Sub MDIForm_QueryUnload(Cancel As Integer, UnloadMode As Integer)
 
    'If a child is active, then unload the child. Otherwise unload MDI
    If UnloadMode = vbFormControlMenu Then
        ' User pressed either Alt+F4 or clicked on the Close (X) button
        If Not Me.ActiveForm Is Nothing Then
            Unload Me.ActiveForm
            Cancel = 1
        End If
    End If
    
End Sub

[RhinoBull]

Since MDI Forms doen't respond to key events and therefore doesn't have KeyPreview property you need to use some api and timer -= I did it for F4 key (Alt+F4 ot CTRL+F4 is little more complicated).
So, place a timer on your MDI form, set Interval = 100, then copy/paste the following code directly to your MDI form:

Option Explicit
 
Private Declare Function GetAsyncKeyState Lib "user32" _
    (ByVal vKey As Long) As Integer
 
Private Const VK_F4 = &H73
 
Private Sub Timer1_Timer()
    If GetAsyncKeyState(VK_F4) Then
        Unload Me.ActiveForm
    End If
End Sub

[jcis]

Try this in your MDI Form

Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
    Dim AltDown
    AltDown = (Shift And vbAltMask) > 0
    If AltDown And KeyCode = vbKeyF4 Then
        Unload MyChildForm 'Use name of the Child Form here
        KeyCode = 0
    End If
End Sub

EDIT
Woops, sorry, you're right Rhino, I didn't know that MDI forms don't have this events.

[iPrank]

Try this in your MDI Form

Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
    Dim AltDown
    AltDown = (Shift And vbAltMask) > 0
    If AltDown And KeyCode = vbKeyF4 Then
        Unload MyChildForm 'Use name of the Child Form here
        KeyCode = 0
    End If
End Sub

EDIT
Woops, sorry, you're right Rhino, I didn't know that MDI forms don't have this events.

jcis, your idea is correct.
Paste it inside every MDIChild, and it will work.
Slightly modified version,

'Inside [b]MDIChild[/b] forms
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
    Dim AltDown
    AltDown = (Shift And vbAltMask) > 0
    If AltDown And KeyCode = vbKeyF4 Then
        Unload [b]Me[/b] ' Unload this form
        KeyCode = 0
    End If
End Sub

If there is no MDIChild, it will unload the MDI form.

Edit: Oh! The MDI form gets unloaded if no child form has focus. May be we should check if there is any activeform in MDIForm_QueryUnload.

[RhinoBull]

...Oh! The MDI form gets unloaded if no child form has focus. May be we should check if there is any activeform in MDIForm_QueryUnload...

Just use what I posted...

[iPrank]

Well ... the truth is .... I didn't like the timer idea.

May be subclassing can give some answer ?

edit: Yes. Yes. I know I use timer a lot. But that's because I can't find any other way.

[RhinoBull]

Well ... the truth is .... I didn't like the timer idea. ...

What's wrong with using timer? As of VB4 release there used to be 15 timers allowed per one form (or entire application - can't recall exactly) but that limitation is long gone...

[iPrank]

Finally it is done ! (I hope)

At first I tried removing the Alt+F4 accleator key from system menu. But hours of google searching didn't give anything.

Now, I'm registering Alt+F4 as hotkey when the MDI activates.

When the MDI deactivates, I'm unregistering the hotkey.

So,the hotkey doesn't effect other windows.