[Mono-winforms-list] Handle being created when I don't expect

[Maser, Dan]

  Well that was the hint I needed to get unstuck.  The assignment of the MdiParent was the first line after the Form was created - and when I inserted the Console.WriteLine I saw right away that the handle was indeed created *before* the assignment of the MdiParent.  Which meant that something in the Form's ctor was causing the handle to be created on mono when it doesn't on MS.

  Using some additional Console.WriteLines I was able to quickly narrow it down to the cuplrit.  The form being created has a System.Windows.Forms.ToolTip member in it, and in the ctor the ToolTip is created.  When the line "m_toolTip.SetToolTip(myWin, String.Empty);" is executed that triggers the handle to be created on mono (and not on MS).

  A simple test app does reproduce this quite easily, so I'll file a bug now.  Many thanks for your patience and help!

  Dan

-----Original Message-----
From: Rolf Bjarne Kvinge [mailto:rolflists at ya.com] 
Sent: Friday, August 10, 2007 11:23 AM
To: Maser, Dan; mono-winforms-list at lists.ximian.com
Subject: RE: [Mono-winforms-list] Handle being created when I don't expect



> -----Original Message-----
> From: Maser, Dan [mailto:Dan.Maser at inin.com]
> Sent: viernes, 10 de agosto de 2007 14:34
> To: Rolf Bjarne Kvinge; mono-winforms-list at lists.ximian.com
> Subject: RE: [Mono-winforms-list] Handle being created when I don't 
> expect
> 
> 
>    That's the first time the HandleCreated event is fired, I have a 
> MessageBox.Show in the first line of the HandleCreated handler and 
> this is the first time I see it.  As such, how can I show you a call 
> stack for the first time the handle is created if this is the first 
> time the HandleCreated event is fired?
> 

I never rely on events for debugging :)
Try overriding CreateHandle and print a stack trace from there (remember to call the base class as well).
You can also override WndProc and watch out for WM_CREATE (0x1) and WM_DESTROY (0x2).

And just before doing:
form.MdiParent = theParent;

Do this:
Console.WriteLine (form.IsHandleCreated) Which will tell you if the handle has already been created or not.

Rolf

>    I wonder if I should hack in some Console.WriteLine statements into 
> the mono source and recompile to see?
> 
>    Dan
> 
> -----Original Message-----
> From: Rolf Bjarne Kvinge [mailto:rolflists at ya.com]
> Sent: Friday, August 10, 2007 6:23 AM
> To: Maser, Dan; mono-winforms-list at lists.ximian.com
> Subject: RE: [Mono-winforms-list] Handle being created when I don't 
> expect
> 
> 
> 
> > -----Original Message-----
> > From: Maser, Dan [mailto:Dan.Maser at inin.com]
> > Sent: jueves, 09 de agosto de 2007 15:15
> > To: Rolf Bjarne Kvinge; mono-winforms-list at lists.ximian.com
> > Subject: RE: [Mono-winforms-list] Handle being created when I don't 
> > expect
> >
> >
> >   Sure. I'm using the latest mono I built from the SVN source on 
> > 08/07/2007.  The call stack with file/line info is really wide, so 
> > I've attached it as a text file to this message.
> >
> 
> When setting MdiParent the handle is being *re*created, not created, 
> and this is matching MS' behavior.
> 
> To know when the handle was created in the first place I'd need 
> another stack trace :)
> 
> Rolf
> 
> >   Thanks!
> >
> > -----Original Message-----
> > From: Rolf Bjarne Kvinge [mailto:rolflists at ya.com]
> > Sent: Thursday, August 09, 2007 2:15 AM
> > To: Maser, Dan; mono-winforms-list at lists.ximian.com
> > Subject: RE: [Mono-winforms-list] Handle being created when I don't 
> > expect
> >
> >
> >
> > >From: mono-winforms-list-bounces at lists.ximian.com
> > [mailto:mono-winforms-list-bounces at lists.ximian.com] On Behalf Of 
> > Maser, Dan
> > >Sent: miércoles, 08 de agosto de 2007 23:49
> > >To: Maser, Dan; mono-winforms-list at lists.ximian.com
> > >Subject: Re: [Mono-winforms-list] Handle being created when I don't 
> > >expect
> > >
> > >  Sorry, that got sent too early.  Here's more of the call stack
> this
> > time.
> >
> >
> > Could you execute with "mono --debug app.exe" so that you get line 
> > numbers as well? And knowing which version of Winforms you're using 
> > would also help
> > :)
> >
> > Rolf
> >
> > >_____________________________________________
> > >From:   Maser, Dan
> > >Sent:   Wednesday, August 08, 2007 4:39 PM
> > >To:     'mono-winforms-list at lists.ximian.com'
> > >Subject:        Handle being created when I don't expect
> >
> > >  I've got a situation with MDI forms where the behavior is
> different
> > >on MS
> > vs mono, but it's proving difficult to get a simple test project 
> > that
> > >reproduces it.  The problem is that in my app setting the 
> > >Form.MdiParent is
> > causing that Form's handle to be created in mono when it doesn't on
> > >MS.NET.   And it doesn't happen for simple test programs on mono 
> > >either;
> > with simple test programs setting the MdiParent property doesn't
> cause
> > the
> > >handle to be created.  I think it must be something about my real 
> > >project
> > that causes this, but the program is so large it's difficult to tell 
> > what that >might be.  Here's a partial call stack from the 
> > Form.HandleCreated event.  Does this info give enough info to 
> > someone to make some guesses about what >could cause the MdiParent 
> > property
> to
> > trigger the HandleCreated in some projects but not in others?
> > >  Thanks in advance for any ideas!
> > > Partial call stack:
> > >at MyChildForm.on_HandleCreated(System.Object sender, 
> > >System.EventArgs
> > >e) at System.Windows.Forms.Control.OnHandleCreated(System.EventArgs
> > >e) at System.Windows.Forms.Form.OnHandleCreated(System.EventArgs e) 
> > >at System.Windows.Forms.Control.WmCreate(Message ByRef m) at 
> > >System.Windows.Forms.Control.WndProc(Message ByRef m) at 
> > >System.Windows.Forms.ScrollableControl.WndProc(Message ByRef m) at 
> > >System.Windows.Forms.ContainerControl.WndProc(Message ByRef m) at 
> > >System.Windows.Forms.Form.WndProc(Message ByRef m) at 
> > >System.Windows.Forms.Control+ControlWindowTarget.OnMessage(Message
> > >ByRef
> > m)
> > >at System.Windows.Forms.Control+ControlNativeWindow.WndProc(Message
> > >ByRef
> > m)
> > >at System.Windows.Forms.NativeWindow.WndProc(IntPtr hWnd, Msg msg, 
> > >IntPtr
> > wParam, IntPtr lParam)
> > >at System.Windows.Forms.XplatUIX11.SendMessage(IntPtr hWnd, Msg 
> > >msg, IntPtr
> > wParam, IntPtr lParam)
> > >at
> >
> System.Windows.Forms.XplatUIX11.CreateWindow(System.Windows.Forms.Crea
> > t
> > ePara
> > ms cp)
> > >at
> >
> System.Windows.Forms.XplatUI.CreateWindow(System.Windows.Forms.CreateP
> > a
> > rams
> > cp)
> > >at
> >
> System.Windows.Forms.NativeWindow.CreateHandle(System.Windows.Forms.Cr
> > e
> > atePa
> > rams create_params)
> > >at System.Windows.Forms.Control.CreateHandle()
> > >at System.Windows.Forms.Form.CreateHandle()
> > >at System.Windows.Forms.Control.WmDestroy(Message ByRef m) at 
> > >System.Windows.Forms.Control.WndProc(Message ByRef m) at 
> > >System.Windows.Forms.ScrollableControl.WndProc(Message ByRef m) at 
> > >System.Windows.Forms.ContainerControl.WndProc(Message ByRef m) at 
> > >System.Windows.Forms.Form.WmDestroy(Message ByRef m) at 
> > >System.Windows.Forms.Form.WndProc(Message ByRef m) at 
> > >System.Windows.Forms.Control+ControlWindowTarget.OnMessage(Message
> > >ByRef
> > m)
> > >at System.Windows.Forms.Control+ControlNativeWindow.WndProc(Message
> > >ByRef
> > m)
> > >at System.Windows.Forms.NativeWindow.WndProc(IntPtr hWnd, Msg msg, 
> > >IntPtr
> > wParam, IntPtr lParam)
> > >at System.Windows.Forms.XplatUIX11.SendMessage(IntPtr hWnd, Msg 
> > >msg, IntPtr
> > wParam, IntPtr lParam)
> > >at System.Windows.Forms.XplatUIX11.DestroyWindow(IntPtr handle) at 
> > >System.Windows.Forms.XplatUI.DestroyWindow(IntPtr handle) at
> > >System.Windows.Forms.NativeWindow.DestroyWindow()
> > >at System.Windows.Forms.Control.DestroyHandle()
> > >at System.Windows.Forms.Control.RecreateHandle()
> > >at 
> > >System.Windows.Forms.Form.set_MdiParent(System.Windows.Forms.Form
> > >value)
> >
> > >....
> > >There's more, but this seems like the relevant part.
> > >
> > >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> 
> 
> 
> 
> 
> 
> --
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> Checked by AVG Free Edition.
> Version: 7.5.476 / Virus Database: 269.11.11/944 - Release Date:
> 09/08/2007 14:44