VB6关闭父窗体时，请在子窗体中卸载queryunload或终止事件

Question

I've asked this question before but I must not have been clear because the answer turned out not to be correct as far as I can tell .. so here goes again.

I have a VB6 application .. it has main menu that opens up Forms and dialogs (not MDI I don't think)

I want to save the position of any open forms or dialogs when the application closes so the next time I open the application the positions will be restored.

I hoped that when I close down the application that ANY of queryUnload, unload, terminate would fire in the 'child' windows or dialogs and I could save their position .. but nothing seems to fire.

I've put break points on all the above events, but when I close down the application nothing gets hit.

VB6 is not my usual gig .. so I'm probably thinking too much .net ..

Is there a way this can be done in VB6 ..

Edit: So it seems if I click the close cross in the top right corner I 'end' the application. Is there a way in VB6 to edit this behavior so I could instigate a graceful close down ?

Answer 1

All 3 events fire, but the Terminate event might not be fired when you expect it.

Create a test project consisting of 1 MDI form, 1 MDI child form, 1 normal form and add the following code:

MDI form:

'MDI form : name=MDIForm1

Option Explicit

Private Sub MDIForm_Click()
  End
End Sub

Private Sub MDIForm_Load()
  Form1.Show
  Form2.Show vbModeless, Me
  WindowState = vbMaximized
End Sub

Private Sub MDIForm_QueryUnload(Cancel As Integer, UnloadMode As Integer)
  MsgBox "MDI form QueryUnload event"
End Sub

Private Sub MDIForm_Terminate()
  MsgBox "MDI form Terminate event"
End Sub

Private Sub MDIForm_Unload(Cancel As Integer)
  MsgBox "MDI form Unload event"
End Sub

MDI child:

'1 form: name=Form1  MDIChild=true

Option Explicit

Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
  MsgBox "MDI child QueryUnload event"
End Sub

Private Sub Form_Terminate()
  MsgBox "MDI child Terminate event"
End Sub

Private Sub Form_Unload(Cancel As Integer)
  MsgBox "MDI child Unload event"
End Sub

Normal form:

'1 form: name=Form2

Option Explicit

Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
  MsgBox "Form2 QueryUnload event"
End Sub

Private Sub Form_Terminate()
  MsgBox "Form2 Terminate event"
End Sub

Private Sub Form_Unload(Cancel As Integer)
  MsgBox "Form2 Unload event"
End Sub

You will see the QueryUnload and Unload events are fired (in this order), but the Terminate event is fired when you close down the MDI form.

When you click the background of the MDI form, then End will be called and no event will be fired

Answer 2

"Child" forms do get the usual events. Notice that on Form_QueryUnload the UnloadMode parameter is vbFormOwner .

"Child" forms are shown with explcit owner form like this:

'--- using global references
Form2.Show vbModal, Form1
Form3.Show , Form1 '--- Form3 is modeless

'--- using instances
With New Form2
    .Show vbModal, oOwnerForm
End With
With New Form3
    .Show , oOwnerForm
End With