MDI Form and MDI Children Question

[jango_fett]

[RESOLVED] MDI Form and MDI Children Question

Hi, all. I'm a newcomer to VB .NET and I'm having a hard time with MDI forms. Specifically, whenever the user attempts to close the MDI form, I need to make sure that all of its children forms are closed. If they are not, I display a message asking the user if they really want to leave.

For example, I state the child form like this:

Friend WithEvents MyChild as frmMDIChild

To open it, the code goes:

MyChild = New frmMDIChild
MyChild.MdiParent = Me
MyChild.Show()

The following code goes in the variable's Closed event:

Private Sub MyChild_Closed(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyChild.Closed
      MyChild = Nothing
End Sub

Then, I code in the MDI form Closing event:

Private Sub frmMDI_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
      If MyChild Is Nothing = False Then
            if MsgBox("There are still open windows. Really exit?", _
MsgBoxStyle.Question + MsgBoxStyle.YesNo, "Exit") _ 
= MsgBoxResult.No Then
            e.Cancel = True
      End If
End Sub

The above code seems to work, but the thing is that I have many children forms and to validate each one of them is overkill. Is there a better way to reference them all at once? Any help would be appreciated. Many thanks!

 

[JohnH]

See if there is something in Form.MdiChildren Property. It is references to all the MDI child forms currently opened in an MDI parent form.

MSDN ref: http://msdn.microsoft.com/library/en-us/cpref/html/frlrfSystemWindowsFormsFormClassMdiChildrenTopic.asp

 

[jango_fett]

Thanks for the link. But I still haven't found a way around my problem. I appreciate the help, though.

 

[JohnH]

Well, that is the answer to the question you asked... if there are MdiChildren of a form then MdiChildren.Length is greater than zero.

 

[jango_fett]

Thanks, JohnH!

Excellent! Thanks, JohnH. I tried out the code shown in the link you provided, but it didn't work the first time. My fault, obviously. But now it did! That was all I needed, thanks. I really appreciate it. You were a great help to me today.